COM 0078.006 1996-1998 - Laserfiche WebLink

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Feum Bio-,agiculturol Services lnc. ?808-328-9760 i$~ip1/97 62:20 PM X414 The Actions of GHB in the Body GHB temporarily inhibits the release of dopamine in the brain. This may cause increased dopamine storage, and later increased dopamine release when the GHB influence wears off [Chin and Kreutzer, 1 992]. This effect could account for the middle-of-the-night wakings common with use of higher GHB doses, and the general feelings of increased well-being, alertness and arousal the next day. GHB also stimules pituitary growth hormone (GH) release. One methodologically rigorous Japanese study reported nine-fold and sixteen- fold increases in growth hormone 30 and 60 minutes respectively after intravenous administration of 2.5 grams of GHB in six healthy men between the ages of twenty-five and forty [Takahara, 1977). GH levels were still seven-fold higher at 120 minutes. The mechanism by which GHB stimulates growth-hormone release is not known. Dopamine activity in the hypothalamus is known to stimulate pituitary release of growth hormone, but GHB inhibits dopamine release at the same time that it stimulates GH release. This suggests that GHB's GH-releasing effect takes place through an entirely different mechanism [Takahara, 1977]. At the same time GH is being released, prolactin levels also rise. Serum prolactin levels increase in a similar time-dependent manner as GH, peaking at five-fold above baseline at GO minutes [Takahara, 1977]. This effect, unlike the release of GH, is entirely consistent with GHB's inhibition of dopamine. Other compounds which lessen dopamine activity in the brain (such as the neuroleptic Thorazine) have been shown to result in prolactin release. Although prolactin tends to counteract many of the beneficial effects of GH, the sixteen-fold increases in GH probably overwhelm the five-fold increases in prolactin.