Journal of Clinical Endocrinology & Metabolism Vol. 58, No. 1 81-86 doi:10.1210/jcem-58-1-81 Copyright © 1984 by the Endocrine Society. Stimulation of Growth Hormone by Vasoactive Intestinal Polypeptide in Acromegaly*KAZUO CHIHARA, HIDESUKE KAJI, NAOTO MINAMITANI, HITOSHI KODAMA, TETSUYA KITA, BUNREI GOTO, TSUTOMU CHIBA, DAVID H. COY and TAKUO FUJITAThird Division, Department of Medicine, Kobe University School of Medicine Kobe 650, Japan; Department of Medicine, Tulane University School of Medicine New Orleans, Louisiana 70112 Address all correspondence and requests for reprints to: Dr. Kazuo Chihara, Third Division, Department of Medicine, Kobe University School of Medicine, 7-chome, Kusunoki-cho, Chuoh-ku,Kobe, Japan. Vasoactive intestinal polypeptide (VIP) was administered as aniv bolus of 1µg/kg BW to 8 acromegalic patients and in doses of 0.5 and 1 µg/kg BW to 15 normal volunteers. Both systolic and diastolic blood pressures decreased, and pulse rate increased transiently after VIP injection. VIP stimulated PRL release from the anterior pituitary in normal subjects. Plasma PRL responses to VIP in women were dose dependent and larger than those in men. Onthe other hand, plasma GH levels rose markedly after VIP injection in all 6 patients with untreated acromegaly. In 2 patients studied after transsphenoidal microadenomectomy, there was no plasma GH response to VIP. In 2 other patients with inactive acromegaly as well as in normal subjects,VIPfailedto affect plasma GH levels. In all 6 patients with active acromegaly, LRH (1-2 µg/kgBW, iv) did not increase plasma GH levels, but TRH (5-10 µg/kg BW, iv) caused significant increases in plasma GH, the magnitude of which was not similar to that of increases seen after VIP injection. Paradoxical GH responses to TRH were not observed in patients in the inactive phase aftertranssphenoidol surgery. These findings suggest that VIP stimulates GH release in vivo in acromegalic patients. A VIP test as well as a TRH test offer promise as simple and reliabletechniques to evaluate the activity of acromegaly, particularly after transsphenoidal surgery.
* This work was supported in part by research grants from theJapanese Ministry of Health and Welfare, the Japanese Ministry of Education, Science, and Culture,and the Growth Science Foundation for 1981 and 1982. Received April 11, 1983. This article has been cited by other articles:
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