Effect of oxytocin and its long-acting analog on milk let-down and intramammary pressure in healthy lactating sows.
Ten healthy lactating sows were given single IV injections of 5 to 10 IU of oxytocin and single IV or IM injections of 0.2 to 0.6 mg of deamino-1-monocarba-(2-O-methyltyrosine)-oxytocin [d(COMOT)]. Studies were done with d(COMOT) concerning the dose-response relationship, the influence of the lactation stage on the duration of the milk let-down effect, and the difference between the IV and IM injections. The mean duration of response was 14 minutes for oxytocin and 6.2 hours for d(COMOT). Intramammary pressure was also measured in 3 sows, using 10 IU of oxytocin IV or 0.6 mg of d(COMOT) IV. Oxytocin resulted in a strong initial increase of the intramammary pressure for about 7 minutes. The d(COMOT) caused the same initial response, followed by secondary oscillations lasting for at least 4 hours.
D000818:Animals; D001835:Body Weight; D005260:Female; D007774:Lactation / Q000187:drug effects*; D007775:Lactation Disorders / Q000188:drug therapy / Q000662:veterinary; D008321:Mammary Glands, Animal / Q000502:physiology; D010120:Oxytocics / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D011247:Pregnancy; D011312:Pressure; D013552:Swine / Q000097:blood; D013553:Swine Diseases / Q000188:drug therapy
D010120:Oxytocics; D010121:Oxytocin; C020731:carbetocin