TY - JOUR
T1 - Pulsatile Growth hormone and prolactin
T2 - Effects of (+) butaclamol, a dopamine receptor blocking agent
AU - Willoughby, J. O.
AU - Brazeau, P.
AU - Martin, J. B.
PY - 1977/10/1
Y1 - 1977/10/1
N2 - Growth hormone (rGH) and prolactin (rPRL) secretory profiles were obtained before and after treatment with a dopamine receptor blocking agent, (+) butaclamol, in 10 male rats chronically implanted with right atrial cannulae. Mean rGH plasma concentrations, determined by planimetry, were reduced (202 ± 20 ng/ml vs. 135 ± 20 ng/ml, P < .01), but the basic configuration and periodicity of rGH secretory bursts were unaltered. Mean rPRL plasma concentrations were elevated (11.1 ± 2.1 ng/ml vs. 65.5 ± 8.1 ng/ml, P < .0005), but rPRL episodic secretion was still apparent. It is concluded that dopaminergic neurons have a minor role in facilitating episodic rGH secretion. Furthermore, persisting episodic rPRL secretion in rats administered a dopamine antagonist suggests that rPRL feedback inhibition does not inactivate the neural mechanism generating episodic rPRL secretion.
AB - Growth hormone (rGH) and prolactin (rPRL) secretory profiles were obtained before and after treatment with a dopamine receptor blocking agent, (+) butaclamol, in 10 male rats chronically implanted with right atrial cannulae. Mean rGH plasma concentrations, determined by planimetry, were reduced (202 ± 20 ng/ml vs. 135 ± 20 ng/ml, P < .01), but the basic configuration and periodicity of rGH secretory bursts were unaltered. Mean rPRL plasma concentrations were elevated (11.1 ± 2.1 ng/ml vs. 65.5 ± 8.1 ng/ml, P < .0005), but rPRL episodic secretion was still apparent. It is concluded that dopaminergic neurons have a minor role in facilitating episodic rGH secretion. Furthermore, persisting episodic rPRL secretion in rats administered a dopamine antagonist suggests that rPRL feedback inhibition does not inactivate the neural mechanism generating episodic rPRL secretion.
UR - http://www.scopus.com/inward/record.url?scp=0017657593&partnerID=8YFLogxK
U2 - 10.1210/endo-101-4-1298
DO - 10.1210/endo-101-4-1298
M3 - Article
C2 - 908278
AN - SCOPUS:0017657593
SN - 0013-7227
VL - 101
SP - 1298
EP - 1303
JO - Endocrinology
JF - Endocrinology
IS - 4
ER -