• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.4
• /
• pp.443-454
• /
• 1998

The present study was attempted to investigate the effect of vasoactive intestinal polypeptide (VIP) on secretion of catecholamines (CA) and to establish whether there is the existence of a noncholinergic mechanism in adrenomedullary CA secretion from the isolated perfused rat adrenal gland. The perfusion into an adrenal vein of VIP $(3{\times}10^{-6}\;M)$ for 5 min or the injection of acetylcholine (ACh, $5.32{\times}10^{-3}\;M$) resulted in great increases in CA secretion. Tachyphylaxis to releasing effect of CA evoked by VIP was not observed by the repeated perfusion. The net increase in adrenal CA secretion evoked by VIP still remained unaffected in the presence of atropine or chlorisondamine. However, the CA release in response to ACh was greatly inhibited by the pretreatment with atropine or chlorisondamine. The releasing effects of CA evoked by either VIP or ACh were depressed by pretreatment with nicardipine, TMB-8, and the perfusion of $Ca^{2+}$-free medium. Moreover, VIP- as well as ACh-evoked CA secretory responses were markedly inhibited under the presence of $(Lys^1,\;Pro^{2.5},\;Arg^{3.4},\;Tyr^6)-VIP$ or naloxone. CA secretory responses induced by ACh and high $K^+\;(5.6{\times}10^{-2}\;M)$ were potentiated by infusion of VIP $(3{\times}10^{-6}M\;for\;5\;min)$. Taken together, these experimental results indicate that VIP causes CA release in a fashion of calcium ion -dependence, suggesting strongly that there exists a noncholinergic mechanism that may be involved in the regulation of adrenomedullary CA secretion through VIP receptors in the rat adrenal gland, and that VIP may be the noncholinergic excitatory secretagogue present in the chromaffin cells.

• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.2
• /
• pp.173-184
• /
• 1998

The present study was undertaken to examine the influence of glucocorticoids on the secretory responses of catecholamines (CA) evoked by acetylcholine (ACh), DMPP, McN-A-343, excess K^+$ and Bay-K-8644 from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. The perfusion of the synthetic glucocorticoid dexamethasone (10-100\;{\mu}M$) into an adrenal vein for 20 min produced a dose-dependent inhibition in CA secretion evoked by ACh (5.32 mM), excess K^+$ (a membrane-depolarizor 56 mM), DMPP (a selective nicotinic receptor agonist, 100\;{\mu}M$ for 2 min), McN-A-343 (a muscarinic receptor agonist, 100\;{\mu}M$ for 4 min), Bay-K-8644 (a calcium channel activator, 10\;{\mu}M$ for 4 min) and cyclopiazonic acid (a releaser of intracellular $Ca^{2+}$, 10\;{\mu}M$ for 4 min). Similarly, the preperfusion of hydrocortisone (30\;{\mu}M$) for 20 min also attenuated significantly the secretory responses of CA evoked by nicotinic and muscarinic receptor stimulation as well as membrane-depolarization, $Ca^{2+}$ channel activation and the release of intracellular $Ca^{2+}$. Furthermore, even in the presence of betamethasone (30{\mu}M$), CA secretion evoked by ACh, excess K^+$, DMPP and McN-A-343 was also markedly inhibited. Taken together, the present results suggest that glucocorticoids cause the marked inhibition of CA secretion evoked by both cholinergic nicotinic and muscarinic receptor stimulation from the isolated perfused rat adrenal gland, indicating strongly that this inhibitory effect may be mediated by inhibiting influx of extracellular calcium as well as the release of intracellular calcium in the rat adrenomedullary chromaffin cells.

• Korean Journal of Veterinary Research
• /
• v.8 no.2
• /
• pp.110-116
• /
• 1968

The mature guinea pigs were grouped as indicated in the table 1. Radio-active iodine(I-131)in dose of 4.5mci, was administered to the experimental groups. The animals were killed for examination in 1, 7, 14, 28, 42, and 55 days after the administration the radio-active iodine. The thyroid and adrenal glands were observed histologically. The results obtained were as follows; 1. One day after the administration, thyroid epithelial cells were abnormally enlarged. After seven days, specimens taken from the middle of the thyroid showed that the follicles and epithelial cells were changing to fibrous tissue, however, some follicles still remained in the verge of the thyroid. Follicles were not observed after fourteen days. After twenty-eight days, the follicles had all changed to fibrous tissue, and had lost their function. 2. The size of the zonas gromerulosa of adrenal cortex epually, in both male and female, showed slight fluctuation in size with no tendency to be changed. 3. Among the zones of the adrenal glands, zona fasciculata showed marked changes. Zona fasciculata was atrophied in Process of time. In females, it was atrophied significantly(P<0.05) after fourteen days, and highly significant (P<0.01) in twenty-eight and fifty-six days after the administration of radioactive iodine. In males, it also decreased significantly(P<0.05) in seventy-eight days and highly significant(P<0.01) in forty-two and fifty-six days after the administration. 4. The size of the Zona reticularis of adrenal cortex in the females increased significantly (P<0.05) in twenty-eight days after the administration. In males, it showed slight fluctuation until twenty-eight days, but it increased significantly(P<0.05) in forty-two and fifty-six days after the administration. 5. The size of the adrenal medulla increased significantly(P<0.05) in twenty-eight and forty-two days in females. It was increased significantly(P<0.05) in fourth-two days and high significantly(P<0.01) in fifty-six days after the administration.

• The Korean Journal of Pharmacology
• /
• v.29 no.1
• /
• pp.43-55
• /
• 1993

The present study was conducted to examine the characteristics of histamine on catecholamine secretion in the isolated perfused rat adrenal gland and to clarify the mechanism of its secretory action. Histamine (37.5 to 150 ug) injected into an adrenal vein evoked a dose-dependent significant secretory response of catecholamines (CA) from the rat adrenal gland. However, upon the repeated injection of histamine (150 ug) at 120 min intervals, CA secretion was rapidly decreased after third injection of histamine. Tachyphylaxis to releasing effects of CA evoked by histamine was observed by the repeated administration. The histamine-induced CA secretion was markedly inhibited by the pretreatment with chlorisondamine, diphenhydramine, ranitidine, $Ca^{++}-free$ Krebs solution, nicardipine and TMB-8 while was not affected by pirenzepine. Moreover, the CA secretion evoked by ACh was considerably reduced by the prior perfusion of histamine $(6.8{\times}10^{-5} M)$ for 30 min. These experimental data suggest that histamine causes secretion of CA in a calcium dependent manner from the perfused rat adrenal gland and that its secretory effect is mediated through activation of both $H_1-$ and $H_2-histaminergic$ receptors located in adrenal medulla, which may be associated with stimulation of cholinergic nicotinic receptors.

• The Korean Journal of Pharmacology
• /
• v.31 no.1 s.57
• /
• pp.63-74
• /
• 1995

It has been known that, during hypoxia, the adrenal medulla is activated to release catecholamines (CA) while hypoxia also inhibits high $K^+$ -induced CA secretion in the cultured bovine adrenal chromaffin cells. The present study was attempted to examine the effect of hypoxia on CA secretion evoked by chlinergic stimulation and membrane-depolarization from the isolated perfused rat adrenal glands and also to clarify its mechanism of action. For this purpose, using the isolated rat adrenal glands, the effects of hypoxia on CA release evoked by nicotinic ($N_1$) and muscarinic ($M_1$) receptor agonists, membrane-depolarizing agent, $Ca^{++}$-channel activator, intracellular $Ca^{++}$-releaser and ACh were determined. Experiments were carried out, perfusing Krebs solution pre-equilibrated with a gas mixture of 95% N_2$ and 5% $CO_2$. Hypoxia was maintained for $3{\sim}4$ hours through the experiments. Hypoxia gradually caused a time-dependent seduction in CA secretion evoked by DMPP ($100{\mu}M$), McN-A-343 ($100{\mu}M$), ACh (5.32 mM), Bay-K-8644 ($10{\mu}M$) and high $K^+$ (56 mM) respectively. How-ever, it did not affect CA secretion evoked by cyclopiazonic acid ($10{\mu}M$). Hypoxia itself also did fail to produce any influence on spontaneous secretory response of CA. These experimental results suggest that hypoxia depresses CA release evoked by both cholinergic stimulation and membrane-depolarization from the isolated rat adrenal medulla, and that this inhibitory activity may be due to the result of the direct inhibition of $Ca^{++}$ influx into the chromaffin cells without any effect on the calcium mobilization from the intracellular store.

• BMB Reports
• /
• v.29 no.5
• /
• pp.393-397
• /
• 1996

Sprague-Dawley male rats (150 g) were chronically treated with 5 v/v % ethanol admixed with nutritionally complete liquid diet and fed ad libitum for 3 weeks. Controls were pair fed with the isocaloric sucrose liquid diet. One half of each group was exposed to cold stress at $4^{\circ}C$ either for 24 h (for determination of mRNA by in situ hybridization) or for 48 h (for determination of enzyme activity). Chronic ethanol treatment (ethanol) did not affect tyrosine hydroxylase (TH) mRNA level in locus coeruleus (LC) of brain and adrenal medulla (AM) compared to controls. Cold stress showed strong increase of TH mRNA level in LC and AM compared to controls. Pretreated ethanol reduced the increased TH mRNA level by cold stress in LC and AM. Ethanol did not affect TH activity in LC and adrenal glands (adrenals). Cold stress increased TH activity in LC but not in adrenals. Pretreated ethanol did not reduce the increased TH activity by cold stress in LC but this result was not shown in adrenals. It is suggested that ethanol does not affect the message level and enzyme protein level for TH in LC and AM in normal rat. It is also hypothesized that pretreated ethanol reduces the magnitude of acute cold stress response, that is induction of TH mRNA in LC and AM, and does not reduce the increased TH enzyme protein that is also acute cold stress response in LC.

• Korean Journal of Animal Reproduction
• /
• v.4 no.1
• /
• pp.35-45
• /
• 1980

The purpose of this experiment was to investigate the effects of castration and administration of testosterone propionate(TP) on the development of the thyroid, adrenal glands and the testis in immature male rats, 25 days immatured, weighing 64.1${\pm}$2g, were divided into two groups of control and castrated, each sub-divided into 30 rats again, treated and untreated with TP respectivity. Each rat was given 20$m\ell$ of TP subcutaneously at two weeks interval. Six rats among each group were randomly sacrificed at 7, 21, 35, 49, and 63 days after treatment, of which their thyroid, adrenal glands and testis were collected for cytometric observation. The results obtained were as follows. 1. The size of the follicle of thyroid glands had a tendency to increase proportionally to the treatment period in every group. However, in castration group, the follicular size of the untreated with TP were significantly increased from 49 days (p<0.05) after treatment than that of the treated with TP, while in control group, the treated with TP were not increased during the treatment period. Regarding the height of the follicular epithelial cell in thyroid gland, the treated with TP had a tendency to increase than the untreated with TP in both castration and control group. 2. Regarding the size of the follicle of thyroid gland in relation with the increment period, the untreated with TP in control group were slightly increased from 49 days after treatment, but the treated with TP were not changed significantly. Castration group had a tendency to increase significantly than the control group, especially the untreated with TP in castration group were significantly increased. 3. As for the change of the relative height of thyroidal follicular epithelial cell in relation with the increment of treatment period, the untreated, A and C group, in both castration and control group were increased at 35 days 63 days after treatment while the treated, B and D group had tendency to increase from 21 days after treatment. 4. Regarding the thickness fo adrenal cortex, the castration group had a tendency to increase than the control group until 21 days after treatment. But, at 35 days, the change of the thickness was reversed; Mean while at 49 days and 63 days, especially C group in castration were significantly increased than any other groups although there were no significant differences among the every group during the whole treatment period. Regarding the thickness of adrenal cortex in relation with the increment of treatment period, A, B and C group had a tendency to increase until 21 days after treatment. After that period, there was no significant increment in all groups. Especially, in D group, there were no significant changes from 7 days to 63 days after treatment. 5. As for the tickness of adrenal medulla, there were no significant changes in every group of castration and TP treatment, except that the castration group had a tendency to increase continually than the control throughout the whole treament period. 6. In terms of the number, diameter and thickness of seminiferous tubule in testis of control group, the treated group with TP were distinctly reduced than those of the untreated group from 49 days after treatment respectively.

• Journal of environmental and Sanitary engineering
• /
• v.5 no.2
• /
• pp.37-43
• /
• 1990

The term of stress was used by many scientists, but there were several difinitions about stress, and this term are using in societies frequently. Generally stress is defined as equilibrium, harmony, and adaptation to external stimulations, in 1930 s Hans Selye was the first scientist who used the term of stress and he pointed out the stress mean the function of force in body. When we get stress the stimulation go to the sympathetic-adrenomedulla system and epinephrine and norepinnephrine are secreted from adrenal medulla. Author tried to investigate the change of catecholamine secretion from rat urine which were exposed to 80 dB noise environment. The control rat urine released 0.03 $\pm$ 0.01 ng/ml of epinephrine and 0.18 $\pm$ 0.04 ng/ml, but in noise exposed group the epinephrine was 0.42 $\pm$ 0.07 ng/ml and norepinephrine was 2.16 $\pm$ 0.48 ng/ml.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.17-17
• /
• 2003

Enzymes involved in catecholamine synthesis are present in the highest concentration in the adrenal medulla, however they were found also in other, mainly nervous tissues. Increased transcription of genes for catecholamine biosynthetic enzymes is an important mechanism to increase the capacity for epineprine/norepinephrine biosynthesis with stress. Gastrodia elata(Chinese name: Tienma), are very important Chinese herbal medicines used for the medical treatment of headaches, migraine, dizziness, epilepsy, rheumatism, neuralgia, paralysis and other neuralgic and nervous disorders. Immobilize stressed rat markedly increased tyrosine hydroxylase (TH) mRNA and dopamine-${\beta}$-hydroxylase (DBH) mRNA transcriptior level more than control group. But treated Gastrodia elata extracts in immobilized stressed rat slightly increased TH mRNA and DBH mRNA transcription level more than normal group. In addition, we are obtained identical results in PC12 cell line. Decrease of transcription level of TH mRNA and DBH mRNA is indicating that Gastrodia elata have a anti-stress effects which decrease the transcription level of TH and DBH mRNA on catecholamine biosynthesis pathway.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10a
• /
• pp.37-37
• /
• 2003

Enzymes involved in catecholamine synthesis are present in the highest concentration in the adrenal medulla, however they were found also in other, mainly nervous tissues. Increased transcription of genes for catecholamine biosynthetic enzymes is an important mechanism to increase the capacity for epineprine/norepinephrine biosynthesis with stress. Gastrodia elata(Chinese name: Tienma), are very important Chinese herbal medicines used for the medical treatment of headaches, migraine, dizziness, epilepsy, rheumatism, neuralgia, paralysis and other neuralgic and nervous disorders. Immobilize stressed rat markedly increased tyrosine hydroxylase (TH) mRNA and dopamine-$\beta$-hydroxylase (DBH) mRNA transcription level more than control group. But treated Gastrodia elata extracts in immobilized stressed rat slightly increased TH mRNA and DBH mRNA transcription level more than normal group. In addition, we are obtained identical results in PC12 cell line. Decrease of transcription level of TH mRNA and DBH mRNA is indicating that Gastrodia elata have a anti-stress effects which decrease the transcription level of TH and DBH mRNA on catecholamine biosynthesis pathway.