Enhancement of aphrodisiac activity in male rats by ethanol extract of Kaempferia parviflora and exercise training.

This study aimed to investigate the effects of Kaempferia parviflora extract (KD) and exercise training on reproductive function in male rats. Sexually mature males were assigned to four groups: control, KD70 (received 70 mg kg(-1) day(-1) for 4 weeks), Ex (exercise training for 4 weeks), Ex + KD70 (exercise training with KD 70 mg kg(-1) day(-1)). At the end of treatment regimes, sexual behaviours including mount latency (ML), mount frequency (MF), ejaculation latency (EL), post-ejaculation latency (PEL), number of mount within 30 min (MF(30)) and number of ejaculation (NEL) were assessed by a video camera, and fertility was tested by natural mating. Results showed that KD had no effect on the weights of reproductive organs, liver, kidneys and levator ani muscle. On the other hand, the weights of epididymis, seminal vesicles, prostate gland and levator ani muscle were significantly increased in the Ex and Ex+KD70 groups. ML and EL were shortened in all treatment groups, but PEL was decreased only in KP70 group. Only Ex and Ex + KD70 groups exhibited lower MF and higher NEL whilst MF(30) were not changed in all groups. None of the treatments altered male fertility. It is concluded that KD enhanced sexual motivation whereas exercise training promoted both sexual motivation and performance.

Effects of Kaempferia parviflora extracts on reproductive parameters and spermatic blood flow in male rats.

Krachaidum (KD, Kaempferia parviflora Wall. Ex. Baker), a native plant of Southeast Asia, is traditionally used to enhance male sexual function. However, only few scientific data in support of this anecdote have been reported. The present study investigated the effects of feeding three different extracts of KD (alcohol, hexane, and water extracts) for 3-5 weeks on the reproductive organs, the aphrodisiac activity, fertility, sperm motility, and blood flow to the testis of male rats. Sexual performances (mount latency, mount frequency, ejaculatory latency, post-ejaculatory latency) and sperm motility were assessed by a video camera and computer-assisted sperm analysis respectively, while blood flow to the testis was measured by a directional pulsed Doppler flowmeter. The results showed that all extracts of KD had virtually no effect on the reproductive organ weights even after 5 weeks. However, administration of the alcohol extract at a dose of 70 mg/kg body weight (BW)/day for 4 weeks significantly decreased mount and ejaculatory latencies when compared with the control. By contrast, hexane and water extracts had no influence on any sexual behavior parameters. All types of extracts of KD had no effect on fertility or sperm motility. On the other hand, alcohol extract produced a significant increase in blood flow to the testis without affecting the heart rate and mean arterial blood pressure. In a separate study, an acute effect of alcohol extract of KD on blood flow to the testis was investigated. Intravenous injection of KD at doses of 10, 20, and 40 mg/kg BW caused dose-dependent increases in blood flow to the testis. The results indicate that alcohol extract of KD had an aphrodisiac activity probably via a marked increase in blood flow to the testis.

Mediation of contraction in rat cauda epididymidis by alpha-adrenoceptors.

Subtypes of alpha-adrenoceptors responsible for contractions of the rat cauda epididymidis were studied in vivo by micropuncture using a servo-nulling pressure transducer system. Administration of both non-selective and selective alpha-adrenoceptor agonists in doses of 1-40 microg noradrenaline kg(-1) body weight (BW), 1-100 microg clonidine kg(-1) BW, or 100-800 mg methoxamine kg(-1) BW enhanced contractions of the proximal cauda epididymidis in a dose-response manner. The potency of the agonists were noradrenaline > or = clonidine>methoxamine. Pre-treatments with selective alpha(1)-adrenoceptor antagonist (prazosin) and alpha(2)-adrenoceptor antagonist (yohimbine) at the doses of 400 and 800 microg kg(-1) BW, respectively, had very little effect on spontaneous contractions, but effectively blocked the responses to the maximal doses of methoxamine and clonidine. The responses could not be explained by the systemic effects of agonists and antagonists. The results suggest that contraction of the proximal cauda epididymidis of rats is mediated by both alpha(1)- and alpha(2)-adrenoceptors. The latter appears to be more abundant.

Structural requirements of some sulphonamides that possess an antifertility activity in male rats.

Sulphonamides with different chemical structures were synthesized and these 13 compounds together with 7 commercially available sulpha drugs were tested for antifertility activity by natural mating in male rats. All compounds were given daily by gastric intubation at doses of 125, 150, 250 or 450 mg/kg for 6 weeks. Sulphapyridine caused a dose-related and reversible reduction in fertility at doses between 125 and 450 mg/kg. At the high dose, fertility was reduced to 25.9% of control at 5 weeks after treatment, and complete recovery occurred by 3 weeks after drug withdrawal. This activity was abolished when the pyridine ring was substituted by other heterocyclic rings, except sulphachloropyridazine which had only weak activity. Replacement of the pyridine ring by a hydrogen atom or short aliphatic chains preserved or even enhanced the potency. Thus, sulphanilamide, N1-methylsulphanilamide or N1-diethylsulphanilamide produced a marked but reversible reduction in fertility. Removal or substitution of the N4-amino group on the benzene ring of sulphapyridine with a methyl group destroyed the activity. However, the bromo or nitro analogue (at the para- but not the meta-position of the benzene ring) still possessed some activity. N4-Acetyl derivatives of sulphapyridine, sulphanilamide, and N1-diethylsulphanilamide were as potent as their parent compounds. These results suggest that the presence of pyridine or other heterocyclic rings is not necessary for the antifertility activity of sulphonamide compounds. However, the N4-amino group is indispensable. In addition, acetylation of this amino group does not change the potency. The prototype of the antifertility sulphonamides therefore seems to be sulphanilamide.

Mode of action of the antifertility sulphonamides: lack of effects on folate metabolism.

The effects of some antifertility sulphonamides on folate metabolism were investigated in the male rat. Subcutaneous injections of sulphanilamide at a dose of 150 mg/kg/day for 6 weeks produced a marked reduction in fertility of the treated animals. This effect was rapidly recovered by one week after drug withdrawal. Similar treatments with trimethoprim (30 mg/kg/day) or pyrimethamine (8 mg/kg/day) had virtually no effect on fertility. The synergistic effect of trimethoprim or pyrimethamine on the antifertility activity of sulphanilamide was not observed when the drugs were administered in combinations. Treatment with sulphapyridine (450 mg/kg/day for 6 weeks) failed to alter the levels of folate in the blood and the reproductive organs except the testes in which accumulation of folic acid occurred. The results suggest that the antifertility activity of sulphanilamide, sulphapyridine and perhaps some other sulphonamides is not associated with the inhibition of folate metabolism.

Free and bound sialic acid in rat and hamster epididymal fluid.

Total, free and bound sialic acid concentrations were determined in sperm-free luminal fluid removed by micropuncture from different regions of the rat and hamster epididymides. In the rat, total sialic acid concentrations (mean +/- s.e.m.) in the proximal caput, the mid corpus and the proximal cauda were, respectively, 25.7 +/- 1.3, 23.9 +/- 1.7 and 28.8 +/- 1.9 mM compared to 4.4 +/- 0.1 mM in blood plasma. In the hamster, total sialic acid concentrations in the distal corpus, the proximal cauda and the distal cauda were, respectively, 32.9 +/- 3.8, 26.4 +/- 1.4 and 26.6 +/- 3.2 mM compared to 4.7 +/- 0.5 mM in blood plasma. Free sialic acid accounted for approximately 70-80% of total sialic acid present in the epididymal plasma of the rat. Similarly, 82% of sialic acid in the rat blood plasma was in free form. The levels of free and bound sialic acid were not changed in different regions of the rat epididymis. Unilateral ligation of the rat efferent ducts had no effect on total, free or bound sialic acid concentrations in all regions except in the proximal cauda in which a transient increase (P less than 0.01) in free sialic acid was observed on Day-3 after EDL.

Hemorrhagic tolerance of rats at sea level after acute exposure to high altitude.

Exposure of rats to a simulated altitude of 5,000 m for 1 and 3 d caused increases in hematocrit (Hct) and in hemoglobin (Hb) concentration and a decrease in total plasma volume (TPV) in comparison with sea level control animals. Total blood volume (TBV) was decreased after 1 d of exposure to altitude but returned to normal in 3 d of altitude exposure. The sea level hemorrhagic tolerance was measured in all animal groups by determining the bleeding volume which resulted in death following cannulation under anesthesia. This was recorded as a bleeding volume index (BVI), the total volume of blood lost per 100 g of body weight. The mean BVI decreased in 1-d altitude rats, but not in 3-d altitude rats. Changes in mean arterial blood pressure and Hct during bleeding were recorded. The decreased hemorrhagic tolerance was suggested to be due in part to a decreased TBV and to a loss in arterial blood pressure (BP) regulatory capability after severe hemorrhage. The results of the present study for acutely altitude-exposed rats are opposite to those of a previous study for chronically altitude-exposed rats in which BVI, TBV, and the ability for arterial BP regulation were increased.