[Regulatory mechanism of hormones of the pituitary-target gland axes in kidney-Yang deficiency based on a support vector machine model]

Objective To study the development mechanism of kidney-Yang deficiency through the establishment of support vector machine models of relevant hormones of the pituitary-target gland axes in rats with kidney-Yang deficiency syndrome. Methods The kidney-Yang deficiency rat model was created by intramuscular injection of hydrocortisone, and contents of the hormones of the pituita- ry-thyroid axis: thyroid stimulating hormone (TSH), 3,3',5-triiodothyronine (T3) and thyroxine (T4); hormones of the pituitary-adrenal gland axis: adrenocorticotropic hormone (ACTH) and cortisol (CORT); and hormones of the pituitary-gonadal axis: luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T), were determined in the early, middle, and advanced stages. Ten support vector regression (SVR) models of the hormones were established to analyze the mutual relationships among the hormones of the three axes. Results The feedback control action of the pituitary-adrenal axis began to lose efficacy from the middle stage of kidney-Yang deficiency. The contents all hormones of the three pituitary-target gland axes decreased in the advanced stage. Relative errors of the jackknife test of the SVR models all were less than 10%. Conclusion Imbalances in mutual regulation among the hormones of the pituitary-target gland axes, especially loss of effectiveness of the pituitary-adrenal axis, is one pathogenesis of kidney-Yang deficiency. The SVR model can accurately reflect the complicated non-linear relationships among pituitary-target gland axes in rats with of kidney-Yang deficiency.