Concentrations of energy substrates in oviductal fluid and blood plasma of pigs during the peri-ovulatory period

Abstract

Summary. Large White gilts, 9 to 18 months old, that had exhibited at least two natural oestrous cycles were divided into three groups (phases): unmated pre-ovulatory, unmated post-ovulatory and mated post-ovulatory (n = 16, 20 and 18). Oviductal luminal fluid samples were collected under anaesthesia by micropipette from the ampulla and ampullary\p=n-\isthmicjunction and analysed by an ultramicrofluorometric technique. Glucose concentrations (mmol l \ m=-\ 1, means combining regions; mean \ m=+-\ sem)were significantly higher in blood plasma than in oviductal fluid (4\m=.\56 \ m=+-\0\m=.\20versus 0\m=.\59\ m=+-\0\m=.\16;P < 0\m=.\0001; n = 27), whereas lactate was higher in the oviduct (5\m=.\71\ m=+-\ 0\m=.\53versus 2\m=.\480\m=.\24;P < 0\m=.\0001; n = 27). No significant differences were found between the ampulla and the ampullary\p=n-\isthmicjunction. However, the concentration of glucose was significantly higher (P < 0\m=.\05) in the ampulla of the pre-ovulatory group (0\m=.\97 \m=+-\0\m=.\20;n = 13) compared with the mated group (0\m=.\25 \m=+-\0\m=.\05;n = 14) and its concentration in the ampullary\p=n-\isthmicjunction in the pre-ovulatory group (1\m=.\65\ m=+-\ 0\m=.\63; n = 13) was significantly greater (P < 0\m=.\05) than in the post-ovulatory (0\m=.\43 \ m=+-\0\m=.\11 ; n = 11) or mated groups (0\m=.\17 \ m=+-\ 0\m=.\02; n = 14). Lactate in the ampulla of mated animals was higher than in the pre-ovulatory group (6\m=.\83 \m=+-\0\m=.\70versus 3\m=.\86\ m=+-\0\m=.\38;P < 0\m=.\05;n = 15 and 13), but neither was significantly different from the post-ovulatory group. Furthermore, no change was seen at the ampullary\p=n-\isthmic junction in lactate concentration with phase. Pyruvate concentrations showed no differences with phase, region or with plasma (oviduct 0\m=.\21\ m=+-\ 0\m=.\02;plasma 0\m=.\14\ m=+-\ 0\m=.\01; n = 27 and 26). Glucose concentration within the oviduct decreased at a time when gametes or embryos, with their liberated cumulus cells, were present. Consequently it is evident that the microenvironment of the gametes and embryos is changing and, in the light of these measurements, the composition of the media used for in vitro culture experiments may require modification to reflect the physiological levels more closely.

Oviduct: roles in fertilization and early embryo development

“…Pyruvate, lactate, lipids and amino acids are present in the oviductal fluid, and the levels of these nutrients fluctuate through the estrous cycle in mice, rabbits, pigs and humans (Nieder & Corder 1982, Nichol et al 1992, Leese et al 1993, Tay et al 1997. The carboxylic acids are processed through immature mitochondria (characterized by the short and less formed cristae, shown in Fig.…”

Porcine sperm capacitation involves tyrosine phosphorylation and activation of aldose reductase

“…The concentrations of glucose in the oviduct fluid, which differ substantially among mammals, have been shown to increase during the preovulatory period of the estrous cycle (Vecchio et al 2010). In pigs, Nichol et al (1992) reported that the concentrations of glucose were significantly lower in the whole oviduct (0.59 mM) than in the blood plasma (4.56 mM), but its concentration in the ampullary-isthmic junction during the preovulatory period (1.65 mM) was greater than during other periods of the estrous cycle. In boar sperm, the utilization of glucose is controlled in part by the heterogeneous localization of GLUT family transporters over the entire sperm surface (Bucci et al 2010).…”

The Fallopian tubes in domestic mammals: how vital is their physiological activity?

“…Furthermore, as detected by electron probe analysis in rodents, there are differences in elemental composition between ampullary and isthmic fluid [18]. Using a surgical approach to regional fluid sampling, a series of differing environments was detected along the duct [19]. Bearing in mind the contractile activity of the myosalpinx, accentuated during the period of oestrus and close to ovulation, a mixing of fluids might have been anticipated, rendering the composition more or less homogeneous.…”