@conference {40577,
	title = {Bovine growth hormone and its effects on the local production of prostacyclin I<sub>2</sub> and mammary blood flow in dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {111-114},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Our objective was to test the hypothesis that bovine growth hormone  
(bGH) can induce the secretion of vasodilators by the bovine mammary gland.   
Three adult lactating cows were surgically implanted with catheters in the left  
costoabdominal artery, in the left subcutaneous abdominal vein (milk vein) and  
in a lymph duct afferent to the left supramammary lymph node.  In addition, a  
transit time flow probe was implanted on the left pubic artery.  Cows were  
injected s.c. with either saline or 25 mg of bGH according to a crossover  
design.  Samples from arterial and venous blood and from lymph fluid were  
collected from 2 hours before to 16 hours after the injection.  Mammary blood  
flow was recorded at each sampling.  Injection of bGH induced a gradual  
increase in mammary blood flow in lactating cows while it remained constant  
after the saline injection.  Venous concentrations of 6-keto-prostaglandin F1a, a  
stable metabolite of the vasodilator prostacyclin I2, were not affected by bGH  
injection.  However, lymphatic concentrations of the prostacyclin I2 metabolite  
increased when cows were injected with bGH.  The time course of the increase  
in plasma IGF-I concentration was similar to that of mammary blood flow and  
6-keto-prostaglandin F1a.  In conclusion, a local release of prostacyclin I2 may  
be responsible for the bGH-induced increase in mammary blood flow.  IGF-I  
might mediate this effect of bGH. 
 },
	issn = {1176-5283},
	author = {Lacasse P and Block E and Couture Y and Petitclerc D}
}
