Maternal and postnatal high-fat diets with high ω6 : ω3 ratios affect the reproductive performance of male offspring in the mouse.

High-fat diets (HFDs) are an acknowledged risk factor for male subfertility, but the underlying mechanisms remain unclear. In the present study we compared the effects of two HFDs with different ω6:ω3 ratios, one enriched with soy oil (SOD; ω6:ω3=9.62) and another enriched with sunflower oil (SFOD; ω6:ω3=51.55), with those of a commercial diet (CD; ω6:ω3=19.87), supplied from pregnancy to adulthood, on morphometric parameters and reproductive performance in adult male mice (recommended ω6:ω3 for rodents=1-6). Bodyweight was significantly higher in the SFOD than CD group, and relative testicular weight was significantly lower in the SFOD than the other two groups. SFOD altered sperm performance: it reduced sperm viability (mean±s.e.m.; 76.00±1.35% vs 82.50±1.45% and 80.63±1.00% in the SFOD vs CD and SOD groups respectively; P<0.05) and increased the percentage of immature spermatozoa (71.88±7.17% vs 51.38±5.87% and 48.00±5.72% in the SFOD vs CD and SOD groups respectively; P<0.05). The epididymal ω6:ω3 ratio was higher in the SFOD versus CD and SOD groups, whereas the unsaturation index was higher in the SOD and SFOD groups than in CD group. Sperm membrane integrity was diminished in both the SOD and SFOD groups, but there was no difference in sperm reactive oxygen species production in these two groups compared with the CD group. The fertilisation rate was lower in the SFOD compared with the CD and SOD groups. In conclusion, although both HFDs affected sperm quality, the fertilising ability was more altered by the excessive dietary ω6:ω3 ratio than by the net ω6 content.

Mouse plasma progesterone levels are affected by different dietary ω6/ω3 ratios.

An imbalance in the dietary polyunsaturated fatty acids (PUFAs) ω6/ω3 ratio, could influence negatively the reproductive performance. The aim of the study was to assess the effects of chronic administration of diets enriched with soybean or sunflower oils with different ω6/ω3 ratios on the reproductive parameters of adult female mice. Mice were fed different diets for 90 days: a commercial diet (CD), a 5 or 10% soy oil-enriched diet (SOD5 and SOD10, respectively), and a 5 or 10% sunflower oil-enriched diet (SFOD5 and SFOD10, respectively). The parameters evaluated were: body weight and food intake, estrous cycle, plasma progesterone concentration, ovulation rate, and oocyte quality. Progesterone concentrations (ng/ml) were significantly higher in the SFOD10: 14.9±2.8 vs CD: 5.4±1.2; SOD5: 5.6±1.1 and SFOD5: 4.6±1.4. Additional parameters evaluated were not affected. However, metestrous and luteal phases were shorter in subjects receiving SOD and longer in those under SFOD diets. In SFOD, there was a trend towards a smaller number of recruited oocytes compared to CD and SOD and a higher percentage of cleaved oocytes were quantified in SOD diets. A 3-month supply of a diet with elevated LA ω6/ALA ω3 ratio to adult female mice affects their reproductive physiology, modifying progesterone production, ovulation rate, and/or oocyte quality. Although some differences in the response to diets have been observed in several mammalian species, the present findings must be taken into consideration when a diet for optimizing reproductive capability is indicated.

Reproductive performance and fertility in male and female adult mice chronically treated with hexarelin.

Hexarelin (HEXr), a synthetic ghrelin analogue, has been associated with modifications of reproductive physiology. In previous studies of adult mice, we detected that HEXr induced significantly reduced ovulation rate and significant correlation coefficients between sexual maturation and corporal weight in offspring. In this study, we investigated the effects of chronic HEXr administration on sperm concentration and functional activity, oestrous cyclicity and pregnancy index, in addition to the number of fetuses and its correlation with the number of corpora lutea. Adult Albino swiss mice were injected (sc) daily with HEXr: 100 µgkg(-1) day(-1) (HEXr D1) or 200 µgkg(-1) day(-1) (HEXr D2) for 53 days in males and 30 days in females. We detected a significantly decreased ratio in the number of fetuses per corpora lutea in females treated with HEXr D2 for 30 days before mating and during the first 6 days of pregnancy, in addition to a downward trend in the pregnancy index and percentage of females impregnated by each male treated with both doses of the analogue. Although we did not find any significant effect on additional parameters evaluated in both genders, we propose certain effects of HEXr on the implantation process and/or early development of embryos and over the in vivo reproductive capability of males.

Inhibitory effects of ghrelin on sexual behavior: role of the peptide in the receptivity reduction induced by food restriction in mice.

Ghrelin (Ghr) is a gut/hypothalamus peptide with inhibitory actions on reproductive physiology; however, there are no previous reports of its role on estrous behavior. Under the hypothesis that the increase of plasma Ghr during food restriction (FR) is responsible for receptivity reduction, we intended to evaluate the receptivity percentage of female mice subjected to: exp. 1) acute and chronic FR and Ghr administration (3 nmol/animal/day, s. c.) and exp. 2) the co-administration of a ghrelin antagonist [ant=(d-Lys3)-GHRP-6; 6 nmol/animal/day s. c.]. All females were ovariectomized, primed with steroids, trained, and randomly subjected every week to each one of several protocols, followed by a behavioral test. Experiment 1 (n=8): basal, no treatment; acute FR (aFR), 24-h fasting; chronic FR (cFR), 50% FR for 5 days; acute ghrelin (aGhr), Ghr 30 min before test and chronic ghrelin (cGhr), Ghr for 5 days. Except for cGhr, all treatments significantly decreased the percentage of receptivity (mean±SEM): basal 61.9±6.0, aFR 33.1±8.1, cFR 18.8±7.7, aGhr 45.6±10.6, p<0.05 vs. basal. In exp. 2 (n=11), except for cFR+ant (55.0±6.4) the co-administration of the antagonist reversed the deleterious effects detected in exp. 1: basal 70.9±5.4; aFR+ant 72.3±7.6; aGhr+ant 73.6±4.7. As expected, the administration of vehicle or antagonist alone did not modify receptivity. Besides, we found a significant correlation between percentage of body weight loss and percentage of receptivity reduction (r=0.62, p=0.0004). This is the first study demonstrating that ghrelin is able to inhibit female mice sexual behavior and that is involved, at least in part, in receptivity reduction after food scarcity.

Effects of hexarelin (a ghrelin analogue) on fertilisation and the pre- and postnatal development of mice.

Ghrelin (Ghr) has been associated with reproductive physiology and pre- and postnatal development. The objectives of the present study were to evaluate the effects of hexarelin (HEX; 100 or 200 microg kg(-1) day(-1)), a therapeutic Ghr analogue, on: (1) embryo development 60 h post ovulation, induced pharmacologically, in pregnant mice; (2) the physical, neurobiological and sexual development of offspring of female mice injected with HEX during the first, second or third week of pregnancy or throughout the entire pregnancy; and (3) adult memory acquisition in these offspring. We also evaluated the effects of chronic HEX administration on memory acquisition in adult mice. Treatment of non-pregnant female mice with HEX decreased ovulation rate. However, treatment of pregnant mice with HEX at any time during pregnancy tended to accelerate offspring maturation, regardless of bodyweight. This effect was only significant on neurobiological parameters following treatment during the first week. HEX treatment during the first week and/or throughout the entire pregnancy resulted in impaired memory acquisition in the offspring, with female mice being more susceptible to these effects. Similar results were observed for the effects of chronic HEX treatment on memory acquisition in adult mice. In conclusion, HEX seems to exert differential effects depending on when it is administered. Because HEX has started to be used therapeutically, its deleterious effects on ovulation and memory acquisition must be further evaluated.

[The correlation between the conventional spermogram parameters and the osmotic resistance tests in patients from among fertile and infertile couples]. / Correlación entre parámetros convencionales del espermograma y la preuba de resistencia osmotica en pacientes integrantes de parejas fertiles o infertiles.

It is well accepted that routine semen analysis is a useful tool for valuation of male potential fertility. In our environment, HOST has been recently applied as an additional approach which early detects structural and/or functional alterations of the sperm membranes. We investigated the possible relationship between some semen parameters and HOST in males from A) fertile couples (23-32 years old; n = 11) and B) sterile couples (25-35 years old; n = 171. Sperm concentration, motility, morphology and HOST (semen incubation in hypoosmotic saline solution-sodium citrate and fructose, 150 m0sm/1--, 37 degrees C during 60 min) were evaluated. In HOST determinations, results higher than 60% of swollen cells are considered within the normal range. In our study, sperm from males of B group showed a significantly lower percentage of hyperhydrated cells than those from A group (55.7 + 2.2% and 70.4 + 2.3% respectively; p < .001). In addition, a significant statistical correlation between HOST vs motility or normal morphology was found. On the contrary, we detected no correlation between HOST vs sperm concentration or volume. We suggest that development and application of HOST as a routine, can play an important role in the evaluation and prognosis of an infertile couple.

Correlación entre parámetros convencionales del espermograma y la preuba de resistencia osmotica en pacientes integrantes de parejas fertiles o infertiles. / [The correlation between the conventional spermogram parameters and the osmotic resistance tests in patients from among fertile and infertile couples]

It is well accepted that routine semen analysis is a useful tool for valuation of male potential fertility. In our environment, HOST has been recently applied as an additional approach which early detects structural and/or functional alterations of the sperm membranes. We investigated the possible relationship between some semen parameters and HOST in males from A) fertile couples (23-32 years old; n = 11) and B) sterile couples (25-35 years old; n = 171. Sperm concentration, motility, morphology and HOST (semen incubation in hypoosmotic saline solution-sodium citrate and fructose, 150 m0sm/1--, 37 degrees C during 60 min) were evaluated. In HOST determinations, results higher than 60

of swollen cells are considered within the normal range. In our study, sperm from males of B group showed a significantly lower percentage of hyperhydrated cells than those from A group (55.7 + 2.2

and 70.4 + 2.3

respectively; p < .001). In addition, a significant statistical correlation between HOST vs motility or normal morphology was found. On the contrary, we detected no correlation between HOST vs sperm concentration or volume. We suggest that development and application of HOST as a routine, can play an important role in the evaluation and prognosis of an infertile couple.

Correlación entre parámetros convencionales del espermograma y la preuba de resistencia osmotica en pacientes integrantes de parejas fertiles o infertiles. / [The correlation between the conventional spermogram parameters and the osmotic resistance tests in patients from among fertile and infertile couples]

It is well accepted that routine semen analysis is a useful tool for valuation of male potential fertility. In our environment, HOST has been recently applied as an additional approach which early detects structural and/or functional alterations of the sperm membranes. We investigated the possible relationship between some semen parameters and HOST in males from A) fertile couples (23-32 years old; n = 11) and B) sterile couples (25-35 years old; n = 171. Sperm concentration, motility, morphology and HOST (semen incubation in hypoosmotic saline solution-sodium citrate and fructose, 150 m0sm/1--, 37 degrees C during 60 min) were evaluated. In HOST determinations, results higher than 60

of swollen cells are considered within the normal range. In our study, sperm from males of B group showed a significantly lower percentage of hyperhydrated cells than those from A group (55.7 + 2.2

and 70.4 + 2.3

respectively; p < .001). In addition, a significant statistical correlation between HOST vs motility or normal morphology was found. On the contrary, we detected no correlation between HOST vs sperm concentration or volume. We suggest that development and application of HOST as a routine, can play an important role in the evaluation and prognosis of an infertile couple.