• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.702-709
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• 1999

The present study was performed to elucidate the effects of extracellular $Ca^{2+}$ on contractile responses in isolated porcine coronary artery ring using by perivascular nerve stimulation (PNS). Especially, the study was focused on the source of $Ca^{2+}$ on $P_{2X}$-purinoceptor mediated muscle contraction which one of $P_2$-purinoceptor subtypes. The following results can be drawn from these studies : 1. The phasic contractions induced by PNS were inhibited with muscarinic receptor antagonist, atropine ($10^{-6}M$). 2. The phasic contractions induced by PNS were significantly inhibited by sequential treatment with atropine and adrenergic neural blocker, guanethidine ($10^{-6}M$). 3. The phasic contractions induced by PNS were inhibited with $P_{2X}$-purinoceptor desensitization by repetitive application of $\alpha$,$\beta$-Me ATP ($10^{-4}M$). 4. The phasic contractions induced by PNS were so weakened in calcium-free medium. 5. The phasic contractions induced by PNS were inhibited with calcium channel blocker, verapamil ($10^{-6}{\sim}5{\times}10^{-6}M$). 6. The phasic contractions induced by PNS on pretreated with verapamil ($10^{-6}{\sim}5{\times}10^{-6}M$) were not changed by $\alpha$,$\beta$-Me ATP ($10^{-4}M$). These results demonstrate that the neurogenic phasic contractions induced by PNS are due to adrenergic-, cholinergic- and $P_{2X}$-purinergic receptors and the origin of $Ca^{2+}$ on $P_{2X}$-purinoceptor mediated muscle contraction is extracellular $Ca^{2+}$ through plasmalemmal $Ca^{2+}$ channels.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.371-378
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• 2007

To understand the role of $PM_{2X}/P_{2Y}$ receptor in cortex region of kidney and renal artery, molecular and functional analysis of $PM_{2X}/P_{2Y}$ receptor by pharmacophysiological skill in conventional swine tissues were performed. In functional analysis of $P_{2Y}$ receptor for vascular relaxation, 2-methylthio adenosine triphosphate, a strong agonist of $P_{2Y}$ receptor, induced relaxation of noradrenaline (NA)-precontracted renal artery in a dose-dependent manner. Strikingly, relaxative effect of ATP, 2-msATP, agonists of $P_{2Y}$ receptor, abolished by treatment of reactive blue 2, a putative $P_{2Y}$ receptor antagonist. In contrast, no significant differences of gene encoding $PM_{2X}/P_{2Y}$ and protein expression in immortalized suprachiasmatic nucleus from brain, primary isolated vascular smooth muscle cells from renal artery of pigs and HEK293 from human embryonic kidney under with/without adenosine triphosphate were observed. Taken together, the relationship between molecular and functional characteristic of $PM_{2X}/P_{2Y}$ receptors in conventional pig should be considered that they are another important factor which regulate the kidney function in swine. Based on this study, we propose the purinergic receptor as well as adrenergic and cholinergic receptors is an essential component of the renal homeostasis.

• The Korean Journal of Pain
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• v.33 no.4
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• pp.326-334
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• 2020

Background: In this study, we sought to evaluate whether systemic propentofylline (PPF) has antiallodynic effects in a rat model of postoperative pain, and to assess the mechanism involved. Methods: After plantar incision, rats were intraperitoneally injected with various doses of PPF to evaluate its antiallodynic effect. To investigate the involved mechanism, rats were intraperitoneally injected with yohimbine, dexmedetomidine, prazosin, naloxone, atropine or mecamylamine, following the incision of the rat hind paws, and then PPF was administered intraperitoneally. The mechanical withdrawal threshold (MWT) was evaluated using von Frey filaments at various time points and serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were measured to determine the inflammatory response level. Results: MWT was significantly increased after intraperitoneal injection of 30 mg/kg of PPF when compared with the control group. Injection of PPF and yohimbine, atropine or mecamylamine showed significant decreases in the MWT, while injection of PPF and dexmedetomidine showed a significant increase. Systemic administration of PPF inhibited the post-incisional increase in serum level of TNF-α and IL-1β. Conclusions: Systemic administration of PPF following surgery presented antiallodynic effects in a rat model of postoperative pain. The antiallodynic effects against mechanical allodynia could be mediated by α-adrenergic and cholinergic receptors.