• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.211-218
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• 1993

The effect of active immunization against porcine somatostatin (SRIF-14) on somatostation and somatotropin secretion profile in 18 gilts was investigated. Gilts were assigned to the following treatments: control (sham injection, n = 6); bovine serum albumin (BSA) (injection of BSA with bacterial protein adjuvant, n = 6); SRIF (injection of BSA-SRIF-14 conjugate with bacterial protein adjuvant n = 6). Serum SRIF and pST were assayed from the blood samples taken on day 7 after the last immunization injection. Anti-SRIF antibody titres were assayed in weekly samples two weeks after the initial immunization to one week after the last immunization. Results revealed that the immunization protocol used in the present investigation failed to produce antibodies capable of neutralizing endogenous somatostatin. In addition, the porcine somatotropin assay revealed no significant differences in baseline pST concentration, mean peak amplitude and number of peaks during a 24 h secretory period among SRIF, BSA and control treatment. There were also no differences in SRIF baseline concentration, peak amplitude, and number of peaks during a 24 h secretory period among any of the three treatments. Circulating concentrations of pST and pSRIF were highly correlated (r = -0.09). Furthermore, anti-SRIF antibody titre was not detected in the serum of the gilts actively immunized against SRIF. These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for changing SRIF and pST secretion profiles of the gilt and thus to enhance performance.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.570-575
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• 2002

Effects of active immunization against native 14-mer somatostatin (SRIF, somatotropin releasing inhibiting factor) and its two 14-mer-somatostatin analogues on the milk production in rat mammary cells were studied. Native SRIF, Tyr11-somatostatin (Tyr11-SRIF), and D-Trp8, D-Cys14-somatostatin (Trp8Cys14-SRIF) were conjugated to bovine serum albumin (BSA) for immunogen preparation. Twenty-four female Sprague-Dawley rats were divided into four groups and immunized against saline (Control), SRIF, Tyr11-SRIF, and Trp8Cys14-SRIF at five weeks of age. Booster immunizations were performed at 7, 9, and 11 weeks of age. SRIFimmunized rats were mated at 10 weeks of age. The blood and mammary glands were collected at day 15 post-pregnancy and -lactation. To measure the amount of milk protein synthesis in the mammary gland, mammary cells isolated from the pregnant and the lactating rats, were cultured in the presence of $^3H$-lysine. No significant differences in growth performance, concentration of growth hormone in the circulation, and the amount of milk protein synthesis were observed among the groups. Inductive levels of serum anti-SRIF antibody in the SRIF and Tyr11-SRIF groups but not in the Trp8Cys14-SRIF group, were significantly higher than that of the control group during the pregnancy and lactation periods. The result suggests that active immunization against native 14-mer SRIF and Tyr11-SRIF was able to induce anti-SRIF antibodies, but did not affect the milk protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.57-61
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• 1996

Four castrated Corriedale sheep were used in an experiment to observe the changes in insulin, growth hormone and cortisol in blood plasma following a prolonged infusion of a high rate of somatostatin (SRIF). The animals wee infused with either saline, 25 or $50{\mu}g/kg/h$ of SRIF for 3 hours. Blood samples wee taken every 20 minutes until 1 hour following the end of the SRIF infusion. Both SRIF infusion levels suppressed the release of insulin into plasma to approximately 3.5 mU/l. The SRIF infusions reduced the concentration of growth hormone to barely detectable levels. Following the withdrawal of SRIF there was a massive release of growth hormone. The plasma concentration of growth hormone reached 60 ng/ml within 20 minutes, the length of the growth hormone discharge was in excess of 1 hour. The extent of the discharge of growth hormone following the SRIF infusions was greater than that suppressed by the infusion. The SRIF apparently caused an increase in the plasma concentration of cortisol at the end of the infusion and following is withdrawal. This is possibly associated with some change in the metabolic rate associated with the suppression of insulin or glucagons release. The present experiment demonstrates that a high rate of SRIF infusion can not completely inhibit the release of insulin into the plasma.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.303-309
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• 1990

In order to have a handle on the availability of eukarvotic peptide hormone precursors, a cDNA encoding angler fish prepro-SRIF I was manipulated so that it can be produced in large quantity from heterologous E. coli cells. Using T7 overexpression system, fusion constructs between the T7 phage coat protein Sl0 and the prepro-SRIF were made and modified as desired. From the host E. coli strain, BL21 DE3, harboring these plasmid constructs, three different SRIF related polypeptides were expressed in large amount and characterized. The results confirm the exact construction and authenticity of the overexpressed proteins from E. coli cells. The importance of this heterologous overexpression in hard to get peptide hormone precursors as well as the suitability of the target peptide hormone SRIF for this approach are discussed.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.27-32
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• 2008

The present study was carried out to develop a sustained release implantable formula of bovine somatotropin (SRIF-BST) and to examine its sustained release effect. The SRIF-BST was produced by coating a solid pellet, which was comprised of BST and an excipient, made of a biodegradable polymer and poloxamer, which are capable of regulating the rate of BST release. The coated membrane of SRIFBST was observed with a field emission scanning electron microscope. The thickness of the coated membrane was approximately $1{\mu}m$, and the pore sizes of the coated membrane surface were below $10{\mu}m$. In dissolution test, the release duration of the SRIF-BST maintained for 10 days, whereas the release duration of the control BST formula maintained for 3 days. In weight gain assay and tibia test of hypophysectomized rats, the release duration of the SRIF-BST treated group was 12 days and the net weight gain was 53.16 g, also the tibia length and strength of the SRIF-BST treated group was increased 10.5% and 23.1% compared with those of the control group, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.929-934
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• 2001

The physiological role of brain somatostatin in the central regulation of feed intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of somatostastin 1-28 (SRIF) at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCI solution were given ad libitum. Feed, water and salt intake were measured during ICV infusion of artificial cerebrospinal fluid (CSF) and SRIF. The feed intake during SRIF infusion on days 2 to 5 increased significantly compared to that during CSF infusion. Water intake, when compared to that during CSF infusion, only increased significantly on day 4. NaCI intake during SRIF infusion was not different from that during CSF infusion. Mean arterial blood pressure (MAP) and heart rate during SRIF infusion were not different from those during CSF infusion. The plasma concentrations of Na, K, Cl, osmolality and total protein during SRIF infusion were also not different from those values during CSF infusion.There are two possible mechanisms, that is, the suppression of brain SRIF on feed suppressing hormones and the direct actions on brain mechanisms controlling feed intake, explaining how SRIF works in the brain to bring about increases in feed intake in sheep fed on hay. The results indicate that brain SRIF increases feed intake in sheep fed on hay.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1182-1189
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• 2007

An intracerebroventricular (ICV) infusion of somatostatin 1-28 (SRIF) was used as a thirst-controlling peptide antagonist to investigate whether or not thirst-controlling peptides are involved in the significant decrease in feed intake during the initial stages of feeding large-type goats on dry forage. A continuous ICV infusion of SRIF was conducted at a small dose of $4{\mu}g$ ml/h for 27 h from day 1 to day 2. Goats (n = 5) were fed roughly crushed alfalfa hay cubes for 2 h twice daily and water was given ad libitum. Feed intake was measured during ICV infusion of artificial cerebrospinal fluid (ACSF) and SRIF. The feed intake during SRIF infusion increased significantly compared to that during ACSF infusion. In comparison to the ACSF treatment, plasma osmolality during the SRIF treatment significantly decreased during the first half of the 2 h feeding period. The factor causing the decrease in plasma osmolality during the ICV infusion of SRIF was a decrease in plasma Na, K, Cl, and Mg concentrations. In comparison to the ACSF infusion treatment, parotid saliva secretion volumes during the 2 h feeding period in the SRIF infusion treatment were significantly larger. While there was no significant difference in cumulative water intake (thirst levels) between the SRIF and the ACSF treatments upon conclusion of the 2 h feeding period, based on the plasma osmolality results it is thought that thirst level increases brought about by alfalfa hay cube feeding in the first half of the feeding period were reduced. It is thought that the somatostatin-induced increases in feed intake during the 2 h feeding period in the present experiment were caused by decreases in plasma osmolality brought about by the somatostatin infusion. As a result, it is suggested that the significant decrease in feed intake during the initial stages of feeding in large-type goats given roughly crushed alfalfa hay cubes, was due to the actions of thirst-controlling peptides.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.665-671
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• 1992

To investigate the effects of immunization against somatostatin (SRIF) on growth rate, feed efficiency and carcass quality; forth-eight Yorkshire gilts ($age=37.5{\pm}4.3d,\;wt=8.2{\pm}1.6kg$) were randomly assigned to one of the following three treatments (1) control, (2) bovine serum albumin (BSA) and (3) SRIF. Cyclic SRIF was conjugated to BSA as the antigen containing 1 mg of SRIF diluted in 3 ml of saline. The conjugate was injected subsutaneously together with bacterial cell protein (BP) adjuvant on both sides of the neck of each gilt as the initial injection with three subsequent booster injections. Throughout the experiment all pigs were fed ad libitum a corn-soy diet containing 20% protein. Body weight and feed intake were measured on a weekly basis. All pigs in the experiment were slaughtered when they approached 101 kg body weight on the weekly weigh day. After slaughter, carcass parameters were analyzed to assess carcass quality. Results revealed that there were no differences among SRIF, BSA and control treatments for average daily gain, feed efficiency and feed intake during the first 5 wk of the experiment and from 6 wk to slaughter. The results for carcass analysis indicated that active immunization against SRIF had no effect on fat content, lean yield, water content and Canadian carcass index These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for the enhancement of pig growth and improvement of feed efficiency and carcass quality.

• Journal of Electrical Engineering and information Science
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• v.1 no.2
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• pp.39-44
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• 1996

An efficient interacting multiple mode(IMM) approach for tracking a maneuvering target with kinematic constraints is described based on the square root information filter(SRIF). The SRIF is employed instead of the conventional Kalman filter since it exhibits more efficient features in handling the kinematic constraints and improved numerical characteristics. The kinematic constraints are considered in the filtering process as pseudomeasurements where the degree of uncertainty is represented by the magnitude of the pseudomeasurement noise variance. The Monte Carlo simulations for the constant speed, maneuvering target are provided to demonstrate the improved tracking performance of the proposed algorithm.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.9-15
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• 2009

The present study was carried out to examine the sustained release effect of the implantable bovine somatotropin (SRI-BST) formula. In the blood profile test in steers, the bovine somatotropin concentration in serum by radioimmunoassay showed the peak concentration on the first day after the implantation of the SRI-BST formula, and concentration proceeded for 5 days (p < 0.05). The insulin-like growth factor-1 concentration showed the peak concentration on the seventh day after implantation of the SRIF-BST formula, and concentration proceeded for 10 days (p < 0.05). The glucose showed the peak concentration on the first day after implantation of the SRI-BST formula, and concentration continued for 3 days (p < 0.05). The blood urea nitrogen showed the lowest concentration on the third day after implantation of the SRI-BST formula, and concentration continued for 7 days (p < 0.05). These results proved that the SRIF-BST formula was the sustained release effects in steers.