Biomaterial Database

Phenylethanolamine N-methyltransferase in the brains of streptozotocin diabetic rats. 1986

K J Fischer, and J K Stewart

Recent evidence suggests that adrenergic neurons in the brainstem and hypothalamus are important for regulation of endocrine and cardiovascular function and the response to stress. Since abnormalities in several of these functions are observed in diabetic subjects, we investigated the effects of streptozotocin-induced diabetes on the activity of the enzyme that converts norepinephrine to epinephrine [phenylethanolamine N-methyltransferase (PNMT)] in the brainstem and hypothalamus of the rat. Enzyme activity was measured in the supernatant of sonicated brain tissues of saline-treated control, diabetic, and insulin-treated diabetic rats. One month after streptozotocin treatment, increases in plasma glucose and food intake occurred; these were restored to control levels by insulin treatment. PNMT activity was approximately 2-fold higher in the brainstem of diabetic rats than in controls (P less than 0.0001), and administration of insulin partially prevented the effects of diabetes on PNMT activity (P less than 0.01 compared to diabetics and P less than 0.05 compared to controls). Brainstem enzyme activity measured in all animals (n = 53) exhibited a significant correlation with plasma glucose concentrations (r = 0.51; P less than 0.001). Diabetes had no apparent effect on PNMT activity in the hypothalamus. These findings are the first to suggest that experimental diabetes alters PNMT activity in the medulla/pons.

UI	MeSH Term	Description	Entries
D007031	Hypothalamus	Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.	Lamina Terminalis,Preoptico-Hypothalamic Area,Area, Preoptico-Hypothalamic,Areas, Preoptico-Hypothalamic,Preoptico Hypothalamic Area,Preoptico-Hypothalamic Areas
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D008526	Medulla Oblongata	The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.	Accessory Cuneate Nucleus,Ambiguous Nucleus,Arcuate Nucleus of the Medulla,Arcuate Nucleus-1,External Cuneate Nucleus,Lateral Cuneate Nucleus,Nucleus Ambiguus,Ambiguus, Nucleus,Arcuate Nucleus 1,Arcuate Nucleus-1s,Cuneate Nucleus, Accessory,Cuneate Nucleus, External,Cuneate Nucleus, Lateral,Medulla Oblongatas,Nucleus, Accessory Cuneate,Nucleus, Ambiguous,Nucleus, External Cuneate,Nucleus, Lateral Cuneate
D010625	Phenylethanolamine N-Methyltransferase	A methyltransferase that catalyzes the reaction of S-adenosyl-L-methionine and phenylethanolamine to yield S-adenosyl-L-homocysteine and N-methylphenylethanolamine. It can act on various phenylethanolamines and converts norepinephrine into epinephrine. (From Enzyme Nomenclature, 1992) EC 2.1.1.28.	Phenethanolamine N-Methyltransferase,Noradrenalin N-Methyltransferase,Noradrenaline N-Methyltransferase,Norepinephrine Methyltransferase,Norepinephrine N-Methyltransferase,Methyltransferase, Norepinephrine,Noradrenalin N Methyltransferase,Noradrenaline N Methyltransferase,Norepinephrine N Methyltransferase,Phenethanolamine N Methyltransferase,Phenylethanolamine N Methyltransferase
D011149	Pons	The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.	Pons Varolii,Ponte,Pons Varolius,Pontes,Varolii, Pons,Varolius, Pons
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D003921	Diabetes Mellitus, Experimental	Diabetes mellitus induced experimentally by administration of various diabetogenic agents or by PANCREATECTOMY.	Alloxan Diabetes,Streptozocin Diabetes,Streptozotocin Diabetes,Experimental Diabetes Mellitus,Diabete, Streptozocin,Diabetes, Alloxan,Diabetes, Streptozocin,Diabetes, Streptozotocin,Streptozocin Diabete
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia