Detection of estrous biomarkers in the body exudates of Kangayam cattle (Bos indicus) from interplay of hormones and behavioral expressions.

Behavioral expressions and biochemical composition of body exudates are significantly altered in concert with the endocrine status, which are all clear indicators of physiological conditions of animals. In this study, we sought to infer about the reproductive physiological status of Kangayam cattle (Bos indicus) by analyzing behaviors, endocrine pattern, and body exudates and further to discover estrous biomarkers so as to facilitate timely artificial insemination/mating and to aid in aspects of conservation of the species. Therefore, in this study, we followed Kangayam cows through pre-estrous to post-estrous phases to correlate the endocrine dependence of biochemical constituents in urine and cervical mucus and sought to identify estrous biomarkers. Behavioral estrus was confirmed in 10 cows, from which urine samples were collected and subjected to determination of LH, FSH, estrogens, progesterone, proteins, and lipids. Furthermore, urinary fatty acids and proteins were profiled using gas chromatography and SDS-PAGE, respectively. The volatile compounds in the urine and cervical mucus were identified by gas chromatography-mass spectrometry analysis. The data revealed that LH, FSH, and estrogen levels increased significantly in estrous urine compared with nonestrous urine, whereas progesterone status was vice versa (P < 0.05). The lipid content was also significantly higher in estrous urine than in pre- and post-estrous urines (P < 0.05). There were also cyclical variations of volatiles and fatty acid profiles across phases of the estrous cycle. More acidic compounds were present in estrous urine, rendering it more acidic, than in pre- and post-estrous urines. Interestingly, oleic acid, which was present as a fatty acid in estrous and post-estrous urines, appeared to be a volatile in post-estrous urine and estrous cervical mucus. In addition, octanoic and butanoic acids were specific to both estrous urine and cervical mucus, indicating their possible candidature as estrous biomarkers. SDS-PAGE analysis showed pronounced expression of a 98 kDa protein in post-estrous urine, which in matrix-assisted laser desorption ionization-time of flight mass spectrometry was identified as albumin. Our results demonstrate multiple biomarkers in estrous urine and specific volatiles in cervical mucus that offer scope to develop viable estrus detection kits for Kangayam cows.

Assessment of urinary volatile compounds and proteins in the female goat Capra hircus: A pilot study to reveal potential indicators of oestrus.

Urine samples of female goats in pro-oestrus, oestrus and post-oestrus phases were analysed for finding oestrus-specific volatile compounds using gas chromatograph-mass spectrometry (GC-MS), and proteins using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS). Fourteen urinary volatile were identified covering all three phases among which four compounds, 1-Tetradecanol, n-Pentadecanol, 3-Methylene tridecane and 2-Ethyl-1-dodecene, were unique to oestrus. Also, oestrus urine contained a 25 kDa protein, which was totally absent in pro-oestrus urine, and less-expressed in post-oestrus urine. This protein revealed to be complement C3 fragment. This pilot study, for the first time, reveals the difference in urinary volatile compounds and proteins in the female goat during the different phases of oestrous cycle. The four unique volatile compounds and a 25 kDa protein that appeared as oestrus-specific in this study warrant further investigation to consider them as urinary biomarkers of oestrus in goats.

Heat shock protein(s) may serve as estrus indicators in animals: A conceptual hypothesis.

The estrous cycle consists of episodic phases that eventually regulate reproduction in non-primate mammals. Females are sexually receptive to males only during estrus phase, which lasts from few hours to 2 days. Estrus detection is crucial for reproductive management of animal herd; however, precise estrus detection method/tools are not available. The analysis of body fluids, e.g., facets of proteomics during recent years is promising in the progression of estrus markers. Specifically, heat shock proteins (HSPs) present in body fluids and reproductive organs could be possibly used as markers of estrus. We note the possible vital roles of hyperthermia, stress and steroid hormones during estrus that could positively regulate the expression of HSPs. To validate our hypothesis, we explained the possible mechanism of production of HSPs, specifically during estrus phase. We recommend intensive research on HSPs to develop credible estrus detection tools in animals.

Modulating role of pheromonal cues from oestrus-specific urine on 3-methylcholanthrene-induced male reproductive toxicity.

Polyaromatic hydrocarbons (PAHs) are persistent organic pollutants that contribute to endocrine/gonadal disruption. This study was designed to investigate the endocrine modulating role of pheromones in alleviating the reproductive toxic effects of 3-MC (3-methylcholanthrene), one of the common PAHs, in rat model. The rats were injected intraperitoneally with 3-MC at a dose of 25 mg kg(-1) BW. The serum levels of testosterone and other biochemical parameters were altered to significant levels in 3-MC-treated rats and oestrus-specific urine exposure restored all these effects to near normal. Although testis weight did not indicate any significant change, sperm and spermatid counts were significantly reduced in 3-MC-treated rats, which became normal in oestrus-urine-exposed rats. Hence, this study suggests that oestrus-specific urinary pheromones have the potential to modulate the endocrine system and alleviate the male reproductive toxic effects produced by 3-MC.

Spermidine may decrease ER stress in pancreatic beta cells and may reduce apoptosis via activating AMPK dependent autophagy pathway.

The risk for diabetes increases with increasing BMI<25. Insulin resistance is the key factor for type 2 diabetes; studies revealed that endoplasmic reticulum stress is the main factor behind this disease. With increase in ER stress, pancreatic beta cells start to undergo apoptosis, leading to a decline in the pancreatic beta cell population. The ER stress arises due to unfolded protein response. Recently, spermidine get importance for increasing the longevity in most of the eukaryotes including yeast, Caenorhabditis elegans, Drosophila and human peripheral blood mononuclear cells via induction of autophagy pathway. Autophagy is also involved in regulation of scavenging of proteins. One of the major cellular pathways for scavenging the aggregated intracellular protein is autophagy. Hence spermidine can be a candidate for the treatment type 2 diabetes. Autophagy genes are regulated by mTOR (mammalian Target Of Rapamycin) dependent or independent pathway via AMPK. Hence either inhibition of mTOR or activation of AMPK by spermidine will play two crucial roles, first being the activation of autophagy and secondly the reduction of endoplasmic reticulum stress which will reduce beta cell death by apoptosis and thus can be a novel therapeutic candidate in the treatment of insulin resistance in type 2 diabetes and preserving pancreatic beta cell mass.