Interactive effects of growth hormone and oestrogen on vascular responses in hypophysectomised female rats

Gustafsson, Helena; Tordby, Anna Wickman; Brandin, Lisa; Hedin, Lars O.; Jonsdottir, Ingibjörg H.

doi:10.1530/eje.0.1460267

Cited by 13 publications

(14 citation statements)

References 35 publications

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“…GHR KO mice had reduced systolic blood pressure, which also has been found in hypophysectomized (Hx) rats (13,24,31). The mechanisms underlying this reduction remain unclear, but it has been speculated that a generally hypotrophic cardiovascular system could be causative (12).…”

Section: Discussionmentioning

confidence: 91%

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

Egecioglu

Andersson²,

Bollano³

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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ström G, Wickman A. Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function. Am J Physiol Endocrinol Metab 292: E1418 -E1425, 2007. First published January 23, 2007; doi:10.1152/ajpendo.00335.2006.-To study the role of the growth hormone receptor (GHR) in the development of cardiovascular structure and function, female GHR genedisrupted or knockout (KO) and wild-type (WT) mice at age 18 wk were used. GHR KO mice had lower plasma renin levels (12 Ϯ 2 vs. 20 Ϯ 4 mGU/ml, P Ͻ 0.05) and increased aortic endothelial NO synthase (eNOS) expression (146%, P Ͻ 0.05) accompanied by a 25% reduction in systolic blood pressure (BP, 110 Ϯ 4 vs. 147 Ϯ 3 mmHg, P Ͻ 0.001) compared with WT mice. Aldosterone levels were unchanged, whereas the plasma potassium concentration was elevated by 14% (P Ͻ 0.05) in GHR KO. Relative left ventricular weight was 14% lower in GHR KO mice (P Ͻ 0.05), and cardiac dimensions as analyzed by echocardiography were similarly reduced. Myograph studies revealed a reduced maximum contractile response in the aorta to norepinephrine (NE) and K ϩ (P Ͻ 0.05), and aorta media thickness was decreased in GHR KO (P Ͻ 0.05). However, contractile force was normal in mesenteric arteries, whereas sensitivity to NE was increased (P Ͻ 0.05). Maximal acetylcholine-mediated dilatation was similar in WT and GHR KO mice, whereas the aorta of GHR KO mice showed an increased sensitivity to acetylcholine (P Ͻ 0.05). In conclusion, loss of GHR leads to low BP and decreased levels of renin in plasma as well as increase in aortic eNOS expression. Furthermore, GHR deficiency causes functional and morphological changes in both heart and vasculature that are beyond the observed alterations in body size. These data suggest an important role for an intact GH/IGF-I axis in the maintenance of a normal cardiovascular system. cardiac structure; cardiac function; vascular structure; vascular function; endothelial nitric oxide synthase; growth hormone receptor-null mice

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Section: Discussionmentioning

confidence: 91%

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

Egecioglu

Andersson²,

Bollano³

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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“…Injection of GH significantly increases the body weight in both adult male and female rats [11][12][13]. There is positive correlation between testosterone and GH [14][15][16].…”

Section: Discussionmentioning

confidence: 99%

Oral Administration of Kaempferia parviflora did not Disturb Male Reproduction in Rats

et al. 2008

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Abstract.To investigate the androgenic effect of Kaempferia parviflora (KP), a Thai herbal plant, adult male rats were randomized into control and KP-treatment groups. Rats were treated orally with water in the control group and with 1,000 mg/kg/day of KP in the treatment group for 45 days. Blood samples were collected on days 10, 20, 30 and 45 for measurement of the serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, progesterone and corticosterone levels. The reproductive and non-reproductive organs were dissected on day 45 and weighed. Mating behavior was also observed on days 20 and 30. Body weight was measured throughout the study period. The results showed that KP induced an increase in body weight compared with the controls. There were no significant differences in the weights of either reproductive (testis, seminal vesicle plus coagulating gland, levator ani muscle plus bulbocarvernosus muscle and glans penis, except the prostate gland) or non-reproductive organs (kidney, adrenal gland and gastracnemius muscle). There were no significant differences in serum levels of either FSH or LH between the two groups. The serum testosterone and progesterone levels were insignificantly lower in the KP group during the first 30 days. The serum corticosterone levels in the KP group were lower than those in the controls throughout the study period and were significantly low on days 20 and 30. There were no significant changes in mating behavior in the rats treated with KP. Although KP affected the body weight and serum corticosterone level, it did not affect mating behavior, reproductive and non-reproductive organ weights or hormones related to the reproductive system in the adult male rats. Therefore, we conclude that the testosterone-like effect of KP did not disturb the hypothalamicpituitary-testicular axis or male reproduction. Key words: Body weight, Kaempferia parviflora, Luteinizing hormone (LH), Mating behavior, Testosterone (J. Reprod. Dev. 54: [375][376][377][378][379][380] 2008) aempferia parviflora Wall. Ex. Baker (KP), commonly referred to in Thai as Krachai Dum, is an indigenous herb that belongs to the Family Zingiberaceae. Nowadays, this plant is considered a Thai national herb. Based on studies using gas chromatographic techniques, many kinds of flavonoid substances, including 7,7,3,5,3,5,7,5,7,7, have been found in KP roots [1,2].KP root has been reported to have anti-gastric ulcer activity by preservation of gastric mucous secretion without inhibition of gastric acid secretion in male rats gavaged with an ether extract of KP [3]. In addition, daily administrations of KP at 20, 200, 1,000 or 2,000 mg/kg is not toxic to adult rats; however, 2,000 mg/kg seems to produce an increase in liver weight and decrease in eosinophil numbers (Chewapat et al. unpublished data).Native Thai people widely use this plant with alcohol or boiling water in traditional medicine to increase male libido and alleviative impotency because they believe this plant has androgenic activity altho...

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“…Testosterone has been to have an anabolic effect during development stages such as puberty [16] and to produce greater increases in muscle size and strength in humans [17]. Furthermore, adult male and female rats injected daily with growth hormone (GH) have significant gains in body weight [18,19], suggesting that GH stimulates the rate of body weight gain. In hypophysectomized male rats, administration of GH combined with TP results in greater body weight gain than GH administration alone [20].…”

Section: Discussionmentioning

confidence: 99%

Effect of Daily Treatment with Thai Herb, Kaempferia parviflora, in Hershberger Assay Using Castrated Immature Rats

et al. 2007

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Abstract. The aim of the present study was to investigate the testosterone-like effect of Kaempferia parviflora (KP). Castrated immature rats were randomized and divided into two groups (control and KP-treatment groups). The rats (n=7-8) were treated daily for 5 days by oral route with water in the control group and 1,000 mg/kg of KP in the treatment group. All rats were decapitated 24 h after their last dose and then blood samples were collected for assay of serum FSH, LH, testosterone, progesterone and corticosterone levels. The seminal vesicles plus coagulating glands, ventral prostate, levator ani muscle plus bulbocavernosus muscle, glans penis, kidneys and the adrenal glands were collected and weighed for organ wet weight. Body weight and weight of food intake were recorded throughout the study period. The results show that relative body weight gain in the KP-treatment group was significantly increased 24 and 48 h after the first dose (P<0.05) and then was indistinguishable from the control group. There were no significant differences in the relative reproductive and non-reproductive organ weights between the groups, although all organ weights, except for the glans penis, tended to increase in the KP-treatment group. The serum testosterone levels were significantly increased in the KP-treatment group. There were no significant differences in the serum FSH, LH, progesterone, or corticosterone levels between the groups, even though the serum progesterone level tended to increase and serum LH level tended to decrease in the KP-treatment group. The present study indicates that KP has no testosterone-like effect on reproduction in male rats.

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Interactive effects of growth hormone and oestrogen on vascular responses in hypophysectomised female rats

Cited by 13 publications

References 35 publications

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

Oral Administration of Kaempferia parviflora did not Disturb Male Reproduction in Rats

Effect of Daily Treatment with Thai Herb, Kaempferia parviflora, in Hershberger Assay Using Castrated Immature Rats

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