Studies on responses to potassium, noradrenaline, serotonin, histamine and prostaglandin F2 alpha, of isolated pudendal arteries from non-lactating goats.
The effects of potassium (K+), noradrenaline (NA), serotonin (5-HR), histamine (Hi) and prostaglandin F2 alpha (PGF2 alpha) were studied on isolated pudendal arteries from non-lactating goats. K+, NA, 5-HT, Hi and PGF2 alpha had concentration-dependent contractile effects on the arteries. The developed tensions were, in order of potencies, 5-HT > NA > PGF2 alpha > Hi > K+. NA induced a significantly higher maximal contractile force than K+, 5-HT, PGF2 alpha and Hi. Pretreatment with cocaine was without significant effect on the contractile response to NA. The contractile response to Hi was totally eliminated by mepyramine. Ca2+ had a concentration-dependent contractile effect on arteries depolarized by 125 mM K+. The results indicate that NA, 5-HT and PGF2 alpha may play essential roles in the regulation of goat mammary blood flow. The response to K+ is highly dependent on extracellular Ca2+. The contractile response to histamine may be mediated via H1-receptors. The in vitro method used is well suited to study the vascular reactivity in different regions of the mammary vascular bed.
Jakobsen
K
K
National Institute of Animal Science, Research Centre Foulum, Department of Animal Physiology and Biochemistry, Tjele, Denmark.
Mikkelsen
E O
EO
Nielsen
M O
MO
D000818:Animals; D001158:Arteries / Q000187:drug effects* / Q000502:physiology; D015237:Dinoprost / Q000494:pharmacology*; D006041:Goats; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D007774:Lactation; D008321:Mammary Glands, Animal / Q000098:blood supply; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology*; D011738:Pyrilamine / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*
D011943:Receptors, Adrenergic, beta; D012701:Serotonin; D006632:Histamine; D015237:Dinoprost; D011738:Pyrilamine; D011188:Potassium; D009638:Norepinephrine