Effect of serotonin on the motility of smooth muscles in teats of lactating cows.
The effects of serotonin, injected into one udder artery, on teat smooth muscle function were investigated in four lactating cows. Motility of longitudinal smooth muscles was recorded by a plethysmographic technique, and sphincter function by measuring milk leakage from the full udder. Serotonin (40, 120 and 360 micrograms) activated teat muscle tonicity and reduced the volume of milk leakage. The effects on longitudinal smooth muscles were reduced by mianserin and ketanserin (0.375, 1.5 and 6 mg) and by methysergide (1.5 mg). These blocking substances were also effective (0.2, 0.6 and 1.8 mg respectively) in antagonizing the inhibiting action of serotonin on milk leakage. It is suggested that serotonin effects are mediated by receptors of the S2-type.
Vandeputte-Van Messon
G
G
Burvenich
C
C
Peeters
G
G
D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D007650:Ketanserin; D007774:Lactation; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000502:physiology; D008784:Methysergide / Q000494:pharmacology; D008803:Mianserin / Q000494:pharmacology; D008893:Milk Ejection / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010880:Piperidines / Q000494:pharmacology; D011247:Pregnancy; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology
D010880:Piperidines; D012702:Serotonin Antagonists; D008803:Mianserin; D012701:Serotonin; D007650:Ketanserin; D008784:Methysergide