Developmental changes in the expression of the GLUT2 and GLUT4 genes in the longissimus dorsi muscle of Yorkshire and Tibetan pigs

Glucose transporter proteins 2 and 4 (GLUT2 and GLUT4) play important roles in glucose transport and energy metabolism. Changes in the levels of GLUT2 and GLUT4 mRNA were measured in longissimus dorsi muscle from the lean Yorkshire and fat Tibetan pig breeds at six different time points (1, 2, 3, 4, 5, and 6 months) with quantitative real-time polymerase chain reactions. The results showed that GLUT2 and GLUT4 mRNA were abundantly expressed in the longissimus dorsi muscle and that the developmental expression patterns were similar in both breeds. Tibetan pigs exhibited higher intramuscular fat and GLUT2 mRNA levels, while Yorkshire pigs exhibited a higher myofiber cross-sectional area (CSA) and GLUT4 mRNA levels. Furthermore, the changes in the GLUT4 mRNA levels were strongly and positively correlated with the CSA over a period of six months. These results exhibit time- and breed-specific expression patterns of GLUT2 and GLUT4, which highlight their potential as candidate genes for assessing adipose deposition and muscle development in pigs. These differences in the expression of GLUT family genes may also have indications for meat quality.

Plasma reproductive hormones in normal and vasectomized Chinese males

Plasma reproductive hormones (testosterone, LH, FSH and prolactin) were measured in 298 normal healthy males aged 30-73 years from rural areas of Sichuan Province, People's Republic of China, and in 505 similar men vasectomized between 1 year and 25 years previously. Age-related increases in LH and FSH but not in testosterone or prolactin were noted in normal men. No adverse effects of vasectomy were observed apart from a 16% increase in mean LH levels in the vasectomized compared to non-vasectomized men of similar ages.