Lecture 10, 30 Sept 2003Chapter 9Vertebrate PhysiologyECOL 437University of ArizonaFall 2003instr: Kevin Boninet.a.: Bret PaschVertebrate Physiology 4371. Cellular and GlandularSecretions, Hormones (CH9)2. Announcementsxx3. Exams in Lab9-10 Randall et al. 2002Remove and Replace ExperimentsExam I, ECOL437 200300.511.522.533.50 102030405060708090100Score out of 100Numbermean 70.09091max 96min 35.5s.d. 18.19955N = 22The Doings for this upcoming Friday, Sept 26, will be presented by Doug Keen(UA, PSIO) who is presently a post-doc in Dr. Andy Fuglevand's lab. Thetitle and abstract for his Doings follows."The Neural and Muscular Control of the Human Extensor Digitorum Muscle."Many of the extrinsic hand muscles responsible for flexion and extension ofthe fingers are single bellied muscles that give rise distally to multipletendons. Current thinking is that these multi-tendoned muscles may be comprised offunctional compartments that each produce force selectively on a singledigit and thereby provide independent control of each finger. We examined thishypothesis at the level of the single motor unit.To whet your appetite, future Doings are as follows:Oct 3 - Kati Gothard (UA, Depts of Psio and Neurology) " Neural andautonomic responses to facial expressions in the Rhesus monkey."Oct 10- Rescheduled MotorBytes - Bob Lansing (UA, Psychology, ProfEmeritus ) Discussion of "Pride and the Daily Marathon" - Movementwithout proprioception: the remarkable story of a person who achievedskilled motor control after having lost it through disease"See you Friday 4-5 pm in 601 Gould-Simpson Bldg.-----------------------------------Cindy Rankin, Ph.D.Dept of Physiologyphone: (520) 621-3104email: [email protected]: BioSci West 274Mail: 101 Gittings Bldg.University of ArizonaTucson, AZ 85721-0093Chap 9. Endocrine System – Glands and HormonesSecretions with consequencesAll cells secrete, butSpecialized secretory cells grouped into glandsSecrete same specialized substance (e.g., hormone)Nervous System neurotransmitter acts near and fastOther secretions, such as hormones, may act moredistantly and over a longer time periodHelpful list of abbreviations on page 357.Four categories of cellular secretions:Autocrine – affect the secreting cell directlyParacrine – affect neighboring cellse.g., histamine and inflammationEndocrine – release into bloodstreamExocrine – release onto epithelial surfacee.g., sweat onto skin, bile into digestive systemPheromone – exocrine secretion to signal otherindividualsNeuroendocrine – secretion from axon terminal intoblood streamGlandular SecretionSecretory Granules/Vesicles –similar to synaptic vesicles butusually largerExocytosis – common releasemechanismRegulation via Calcium –remember that free cytosoliccalcium concentration iscorrelated with exocytosis(including of NT, hormones,etc.)9-2 Randall et al. 2002Storage before SecretionLarge molecules easily stored because can’t leave readilySmall molecules often stored bound to accessory proteinsSome molecules actively/continuosly taken into vesiclesSteroid hormones (lipid soluble) tend to leak out soonHydrophobic steroid and thyroid hormonesmove in blood bound to carrier proteinsGlandular SecretionResponse to stimulusHormoneNeurotransmitterAction Potentialetc. (e.g., osmolarity and ADH)1Delivery Vesicle formationEndoplasmicReticulumGolgiTransfervesicleApicalmembraneBasolateralmembraneSecretoryvesicleSecretion239-6 Randall et al. 2002Endocrine - release into bloodstream - secretions called hormonesExocrine - release onto epithelial surface - via duct onto epithelial surfaceGlands…-often in sol’n called primary fluid (salt, water, etc.)-incl. saliva, bile salts, pheromones, salt glands9-9 Randall et al. 2002Hormones: - synthesized by specific tissues - carried in bloodstream to site of action - cause change in activity of target tissueEndocrine Glands-Hormone action often amplified by second messenger cascade-Hormones often released in very low concentrations9-10 Randall et al. 20029-9 Randall et al. 2002Hormone TypesAmines – small (e.g., epi, norepi, thyroid)Eicosenoids from arachodonic acid (prostaglandins etc.)Steroid Hormones from cholesterol (e.g., testosterone, estrogen)Peptide Hormones – common,large, complex(e.g., insulin)(autocoids = otherslike histamine andserotonin)9-11 Randall et al. 2002Feedback...NoFeedbackNegativeFeedback9-12 Randall et al. 20029-1 Randall et al. 2002Neuroendocrine SystemsNeurosecretory cellssecrete neurohormonesAxon terminates intoneurohemal organNeurohormones often [effect]other glands/hormones9-14 Randall et al. 20029-8 Randall et al. 2002Major Players:Pituitary (9 hormones)1. Anterior (~nonneuronal)2. Posterior (~neuronal control)Neuroendocrine SystemHypothalamus - (~7 neurohormones) - mostly peptides(Portal Vessels)9-15 Randall et al. 2002Example:Neuroendocrine SystemHypothalamus-corticotropin-releasing hormoneIn response to cold,fright, pain etc…Portal vesselAnterior Pituitary-Adrenocorticotropin (ACTH)Adrenal Cortex(corticosterone;stress hormones)Blood StreamResponse (lizard example)9-15 Randall et al. 2002Neuroendocrine SystemTropic hormones = act on otherendocrine tissues(e.g., adrenal cortex,thyroid, gonads)NegativeFeedbackAnterior Pituitary9-16 Randall et al. 2002Randall et al. 2002Neuroendocrine SystemPosterior PituitaryOxytocin – uterinecontractions, milk ejectionAntidiuretic Hormone (ADH)- water retention in kidneyBoth are peptide hormonesBoth are similar and highlyconserved9-17 Randall et al. 2002Neuroendocrine SystemPosterior PituitarySimilar, highly conserved peptide hormonesADHRandall et al. 2002Hormone ACTION! (receptors etc.)1. Lipid Soluble2. Lipid Insoluble- Steroid and Thyroid Hormones (~long-lived)- Bind Cytoplasmic Receptors, then to Nucleus- Directly affect transcription (therefore long-term)- Through Membrane- Bind cell-surface receptors- Often one or more 2nd messengers- Amplification- Rapid, short-duration responsesHormone ACTION!(receptors etc.)1. Lipid Soluble2. Lipid Insoluble9-18 Randall et al. 2002Possible 2nd messengers:Hormone ACTION! (receptors etc.)2. Lipid Insoluble Hormones and Intracellular Signaling1. cAMP, cGMP (cyclic nucleotide monophosphates)2. IP3, DAG (diacylglycerol; inositol phospholipids)3. Ca2+ ionsGeneral Model of Hormone Bindingand Intracellular Signaling:A few receptors with direct catalytic activity, but mostvia 2nd messengers :1. cAMP (cyclic nucleotide