Summary: Polyamines are polycationic molecules that contain two or more amino groups (–NH₃⁺) and are present in all eukaryotic and prokaryotic cells. Polyamines are synthesized from arginine, ornithine, and proline, and from methionine as the methyl-group donor. In the traditional pathway for polyamine synthesis, arginase converts arginine into ornithine, which is decarboxylated by ornithine decarboxylase (ODC1) to generate putrescine. The latter is converted to spermidine and spermine. Recent studies have indicated the existence of ‘non-classical pathways’ for the generation of putrescine from arginine and proline in animal cells. Specifically, arginine decarboxylase (ADC) catalyzes the conversion of arginine into agmatine, which is hydrolyzed by agmatinase (AGMAT) to form putrescine. Additionally, proline is oxidized by proline oxidase to yield pyrroline-5-carboxylate, which undergoes transamination with glutamate to produce ornithine for decarboxylation by ODC1. Intracellular production of polyamines is controlled by antizymes binding to and inactivating ODC1. Polyamines exert effects that include stimulation of cell division and proliferation, gene expression for the survival of cells, DNA and protein synthesis, regulation of apoptosis, oxidative stress, angiogenesis, and cell–cell communication activity. Accordingly, polyamines are essential for early embryonic development and successful pregnancy outcome in mammals. In this paper the main concepts on the history, structure and molecular pathways of polyamines as well as their physiological role on angiogenesis, and reproductive physiology are reviewed.

This study aimed to examine the efficacy of Doppler and B-mode sonography in evaluating the impact of maternal temperament on hemodynamic alterations in both the fetus and uterus during ovine gestation in addition to alteration of the angiogenic protein expression and fetal biometry. Twenty Ossimi ewes were divided into two groups, more reactive (MR: 12 sheep) and less reactive (LR: 8 sheep). Several endpoints were assessed every 2 weeks (wk) from breeding to wk 20 of pregnancy. Blood samples were taken to evaluate the expression of angiogenic proteins at parturition. The resistance (RI) and pulsatility (PI) indexes of the uterine (UtA) and fetal umbilical arteries (UMA) were measured. Biometry includes: diameter of amniotic vesicles (AVD), umbilicus (UMD), fetal thoracic diameter (FTD) and metacarpal length (MCL). The UtA-PI was higher in MR compared to LR ewes between 6-12 wks of gestation (P>0.01), while a tendency was recognized at wk 14 (P=0.054). The same was true for UtA-RI during the first 8 wk of pregnancy (P < 0.03) when MR and LR animals were compared. Similarly, UMA-RI was higher in fetuses of MR than LR ewes at wk 14 (P<0.0003) and 20 (P<0.02) of pregnancy. The differences in UMA-PI reached significance at wk 6, 8, 10, and 20 (P<0.0 -0.003). Furthermore, significant changes in fetal biometry were investigated. The expressions of VEGF, NOS3 and HIF 1α were increased in the less reactive sheep (P<0.001). In conclusion, the maternal temperaments affect the Doppler, B mode as well as the expressions of mRNAs for VEGF, NOS3 and HIF 1α genes at time of parturition.

Artificial insemination (AI) is considered as the most efficient feasible tool to improve the dairy cows’ profitability and productivity. In bovines, AI helps to promote genetic improvement and can positively impact the rural economy. The achievement of education in rural populations was one of the Millennium Development Goals (MDGs), made by the United Nations. During the last World Summit on Sustainable Development (WSSD), it was concluded that most of the world’s poor, illiterate and undernourished population lives in rural areas; therefore, access to education is considered one of the greatest challenges for governments in countries with developing economies. To determine the effects of a theoretical-practical training program related to rural management and leadership, AI, and bovine genetic improvement, on the perception and level of knowledge in a rural Colombian population that has been affected by the armed conflict. Phase 1. Included the practical and theoretical training of undergraduate animal sciences students in three dimensions rural management; leadership (D-ML), AI in bovines (D-AI), and genetic improvement (D-GI) after training students were evaluated and selected according to their skills, characteristics, solidarity skills, and their social sensitivity was identified. Phase 2. Included the socioeconomic characterization and training of rural residents by students and field experts in three dimensions D-ML, D-AI, and D-GI. After training we evaluated the perception and level of knowledge before and after training in 63 rural residents using an evaluative instrument. The data before and after (post-test) of the theoretical-practical training, were analyzed to obtain a statistical significance. The perception of knowledge in rural residents was low for general knowledge (2.48±0.76, p ˂ 0.05), D-ML (2.89±1.18, p ˂ 0.05) and D-AI and D-GI (2.17±0.83, p ˂ 0.05). On the other hand, before the theorical-practical training the level of general knowledge was 45.9%, however, after the training increased at 77.6% (p<0.01), while the level of knowledge for the D-AI was increased from 38.5 % to 80.6 % (p ˂ 0.05) after training. Regarding the level of knowledge for the D-GI pre-training was 50.8 and increased to 73.0% (p<0.01) then after. Finally, the level of knowledge for the D-ML was increased (p<0.01) from 54.8 before training to 75% after training. Altogether, the rural extension programs contribute to the closing of knowledge gaps in relation to the use of reproductive biotechnologies and bovine management in rural areas affected by armed conflict.

Exercise physiology in Colombian Creole Horses remains poorly characterized despite the breed’s extensive use in athletic activities. The objective of this study was to evaluate exercise-induced changes in blood biochemical and gas parameters and to determine whether these responses differed according to sex, geographic origin, or gait modality. An analytical observational study with repeated measures was conducted in 76 athletic CCHs. Blood samples were obtained from the jugular vein at rest and immediately after exercise to measure acid–base indicators (pH, carbon dioxide pressure, bicarbonate), electrolytes (sodium, potassium, calcium, chloride), and metabolic variables (glucose, lactate, creatinine). Within-subject comparisons were performed to quantify exercise-induced changes, and subgroup analyses were conducted by sex, geographic region, and gait modality. Exercise resulted in physiologically consistent responses, including a mild reduction in pH (−0.01), decreases in carbon dioxide pressure (−2.39 mmHg) and bicarbonate (−1.7 mmol/L), and a moderate increase in lactate (+2.96 mmol/L), indicating exercise-associated metabolic acidosis and anaerobic metabolism. Glucose and creatinine also increased modestly, while electrolyte concentrations remained relatively stable. No meaningful differences were detected between sexes or geographic regions. As expected, gait modality significantly influenced acid–base responses, with horses performing trocha exhibiting greater reductions in carbon dioxide pressure and bicarbonate. These findings indicate that gait type modulates the magnitude of exercise-induced acid–base responses in Colombian Creole Horses.