natgillin/translations-raw huggingface dataset:
An Extended One-Generation Reproductive Toxicity Study will provide information on the effects of repeated exposure to a chemical during all phases of the reproductive cycle, as necessary.
OECD (2011), Guidance Document on the Current Implementation of Internal Triggers in the Extended One Generation Reproductive Toxicity Study in the United States and Canada, Series on Testing and Assessment, No.
In particular, the study provides information on the reproductive system, and on development, growth, survival, and functional endpoints of offspring up to PND 90.
117, ENV/JM/MONO(2011)21, OECD, Paris.
Interpretation of the results of the study should take into account all available information on the chemical, including physico-chemical, TK and toxicodynamic properties, available relevant information on structural analogues, and results of previously-conducted toxicity studies with the test chemical (e.g. acute toxicity, toxicity after repeated application, mechanistic studies and studies assessing if there are substantial qualitative and quantitative species differences in in vivo/in vitro metabolic properties).
151, OECD, Paris.
Gross necropsy and organ weight results should be assessed in context with observations made in other repeat-dose studies, when feasible.
Meritve in opazovanja, vključena v sklop funkcionalnih opazovanj (kohorta 2A)
Decreases in offspring growth might be considered in relationship to an influence of the test chemical on milk composition (29).
Domača kletka in na terenu
Cohort 2 (Developmental neurotoxicity)
Gibalne
Neurobehavioral and neuropathology results should be interpreted in the context of all findings, using a weight-of-evidence approach with expert judgment.
Fiziološke
The evaluation of developmental neurotoxicity, including human epidemiological studies or case reports, and experimental animal studies (e.g. toxicokinetic data, structure-activity information, data from other toxicity studies) should be included in this characterisation.
Drža
For guidance on the interpretation of developmental neurotoxicity results, refer to test method B.53 (35) and Tyl et al., 2008 (31).
Enostaven prenos
Cohort 3 (Developmental immunotoxicity)
Temperatura
Suppression or enhancement of immune function as assessed by TDAR (T-cell dependent antibody response), should be evaluated in the context of all observations made.
Neprostovoljni klonični in tonični
Significance of the outcome of TDAR may be supported by other effects on immunologically-related indicators (e.g. bone marrow cellularity, weight and histopathology of lymphoid tissues, lymphocyte subset distribution).
Enostavno ravnanje
Effects established by TDAR may be less meaningful in case of other toxicities observed at lower exposure concentrations.
Zaprtost očesne veke
OECD Guidance Document 43 should be consulted for aid in the interpretation of reproduction and neurotoxicity results (26).
Tonus mišic
Whitby (2006), “A Tiered Approach to Life Stages Testing for Agricultural Chemical Safety Assessment”, Critical Reviews in Toxicology, 36, 69-98.
Odziv zenic
Forsythe (1999), “Phytoestrogen Content of Purified Open and Closed Formula Laboratory Animal Diets”, Lab.
Piloerekcija
Sci., 49, 530- 536.
Odziv na pristop
Moser, V.C., I. Walls and T. Zoetis (2005), “Direct Dosing of Preweaning Rodents in Toxicity Testing and Research: Deliberations of an ILSI RSI Expert Working Group”, International Journal of Toxicology, 24, 87-94.
Velikost zenic
Goodman (1999), “Stimulating Research to Improve the Scientific Basis of Risk Assessment”, Toxicological Sciences, 49, 1-4.
Slinjenje
Palmer (1995), “Detection of Effects on Male Reproduction — a Literature Survey”, Journal of the American College of Toxicologists, 14, 293-327.
Odziv na dotik
Mangelsdorf, I., J. Buschmann and B. Orthen (2003), “Some Aspects Relating to the Evaluation of the Effects of Chemicals on Male Fertility”, Regulatory Toxicology and Pharmacology, 37, 356-369.
Solzenje
“Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats — overview of the studies”, Journal of Toxicological Sciences, 25, 1-21.
Odziv na slušni dražljaj
, “Evaluation of Testicular Toxicology: A Synopsis and Discussion of the Recommendations Proposed by the Society of Toxicologic Pathology”, Birth Defects Research, Part B, 68, 408-415.
Oddajanje glasov
Cooper (2007), “The Rodent Estrous Cycle: Characterization of Vaginal Cytology and its Utility in Toxicological Studies”, Birth Defects Research, Part B, 80 (2), 84-97.
Odziv na stiskanje repa
, “Cycles and Seasons”, in C.R.
Dvigovanje
I. Germ Cells and Fertilization, Cambridge, New York.
Posturalni odziv
Reynolds (1999), “Interpreting the Toxicologic Significance of Alterations in Anogenital Distance: Potential for Confounding Effects of Progeny Body Weights”, Reproductive Toxicology, 13:
Anomalije pri hoji
Weiner (1977), “Preputial Separation as an External Sign of Pubertal Development in the Male Rat”, Biological Reproduction, 17, 298-303.
Razširjenost prstov pri pristanku
, “Use of SRBC Antibody Responses for Immunotoxicity Testing”, Methods, 41, 9-19.
Vzburjenost
Herzyk (2004), “Primary Antibody Response to Keyhole Limpet Hemocyanin in Rat as a Model for Immunotoxicity Evaluation”, Toxicology, 197, 23-35.
Moč oprijema s prednjimi okončinami
Gray, L.E., J. Ostby, J. Ferrell, G. Rehnberg, R. Linder, R. Cooper, J. Goldman, V. Slott and J. Laskey (1989), “A Dose-Response Analysis of Methoxychlor-Induced Alterations of Reproductive Development and Function in the Rat”, Fundamental and Applied Toxicology, 12, 92-108.
Stereotipije
Killian (1978), “Daily Sperm Production and Epididymal Sperm Reserves of Pubertal and Adult Rats”, Journal of Reproduction and Fertility,54, 103-107.
Moč oprijema z zadnjimi okončinami
Suarez (1991), “The Method of Sperm Collection Significantly Influences Sperm Motion Parameters Following Ethane Dimethanesulfonate Administration in the Rat”.
Nenormalno vedenje
Reproductive Toxicology, 5, 39-44.
Madeži
Wise (1996), “Methods for Assessing Sperm Motility, Morphology, and Counts in the Rat, Rabbit, and Dog: a Consensus Report”, Reproductive Toxicology, 10, 237- 244.
Anomalije pri dihanju
Russell and S. Schrader (1992), “Methods for Assessing Rat Sperm Motility”, Reproductive Toxicology, 6, 267-273.
Kemikalija
Suarez (1992), “Direct Effects of Ethane Dimethanesulphonate on Epididymal Function in Adult Rats: an In Vitro Demonstration”, Journal of Andrology, 13, 409-421.
snov ali zmes.
Perreault (1991), “Rat Sperm Motility Analysis: Methodologic Considerations”, Reproductive Toxicology, 5, 449-458.
Preskusna kemikalija
Perreault (1993), “Computer-Assisted Sperm Analysis of Rodent Epididymal Sperm Motility Using the Hamilton-Thorn Motility Analyzer”, Methods in Toxicology, Part A, Academic, Orlando, Florida. pp. 319-333.
vsaka snov ali zmes, preskušana s to preskusno metodo.
Smith (1989), "The Automated Analysis of Rat Sperm Motility Following Subchronic Epichlorhydrin Administration: Methodologic and Statistical Considerations", Journal of Andrology, 10, 401-415.
B.57 PRESKUS STEROIDOGENEZE CELIC H295R
Suarez (1992), “Endpoints of Spermatoxicity in the Rat After Short Duration Exposures to Fourteen Reproductive Toxicants”, Reproductive Toxicology, 6, 491-505.
Ta preskusna metoda ustreza Smernici za preskušanje OECD (TG) št. 456 (2011).
OECD (2008), Guidance Document on Mammalian Reproductive Toxicity Testing and Assessment, Series on Testing and Assessment, No 43, ENV/JM/MONO(2008)16, OECD, Paris.
OECD je leta 1998 začela z izvajanjem prednostne dejavnosti, da bi pregledala obstoječe in razvila nove smernice za odkrivanje in preskušanje kemikalij, ki bi lahko povzročale endokrine motnje.
Working, P.K., M. Hurtt (1987), “Computerized Videomicrographic Analysis of Rat Sperm Motility”, Journal of Andrology, 8, 330-337.
Temeljni okvir OECD iz leta 2002 za preskušanje in oceno povzročiteljev endokrinih motenj (OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupting Chemicals), zajema pet ravni, pri čemer vsaka raven ustreza posamezni stopnji biološke kompleksnosti (1).
Bolin, B., R. Garman, K. Jensen, G. Krinke, B. Stuart, and an ad Hoc Working Group of the STP Scientific and Regulatory Policy Committee (2006), “A “Best Practices” Approach to Neuropathologic Assessment in Developmental Neurotoxicity Testing — for Today”, Toxicological Pathology, 34, 296-313.
Za preskus steroidogeneze celic H295R in vitro (H295R), opisan v okviru te preskusne metode, se uporablja adenokarcinomska celična linija človeka (celice NCI-H295R), pri čemer preskus predstavlja raven 2 'preskusa in vitro za zagotavljanje mehanističnih podatkov', ki se uporablja za namene presejanja in prednostnega razvrščanja.
Stütz, N., B. Bongiovanni, M. Rassetto, A. Ferri, A.M. Evangelista de Duffard, and R. Duffard (2006), “Detection of 2,4-dichlorophenoxyacetic Acid in Rat Milk of Dams Exposed During Lactation and Milk Analysis of their Major Components”, Food Chemicals Toxicology, 44, 8-16.
Priprava in standardizacija preskusa kot presejalnega preskusa za odkrivanje kemičnih učinkov na steroidogenezo, zlasti proizvajanje 17β-estradiola (E2) in testosterona (T), sta bili izvedeni v postopku, ki ga sestavlja več korakov.
Forsythe (2007), “Variations in Phytoestrogen Content between Different Mill Dates of the Same Diet Produces Significant Differences in the Time of Vaginal Opening in CD-1 Mice and F344 Rats but not in CD Sprague Dawley Rats”, Environmental health perspectives, 115(12), 1717-1726.
Preskus celic H295R je bil optimiziran in validiran (2) (3) (4) (5).
Sobotka (2008), “Identification and Interpretation of Developmental Neurotoxicity Effects: a Report from the ILSI Research Foundation/Risk Science Institute Expert Working Group on Neurodevelopmental Endpoints”, Neurotoxicology and Teratology, 30:
Cilj preskusa je zagotoviti odgovor DA/NE na vprašanje o možnosti, da bi kemikalija povzročila ali zavirala proizvodnjo T in E2, vendar je mogoče v nekaterih primerih dobiti tudi kvantitativne rezultate (glej odstavka 53 in 54).
OECD (1996), Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, OECD Guideline for Testing of Chemicals, No 422, OECD, Paris.
Rezultati preskusa so izraženi kot relativne spremembe v proizvodnji hormonov v primerjavi s kontrolnimi vzorci s topilom (KVT).
Chapter B.43 of this Annex, Neurotoxicity Study in Rodents
Namen preskusa ni zagotoviti posebnih mehanističnih informacij glede interakcije preskusne kemikalije z endokrinim sistemom.
OECD (2000), Guidance Document on the recognition, assessment, and use of clinical signs as humane endpoints for experimental animals used in safety evaluations, Series on Testing and Assessment, No 19, ENV/JM/MONO(2000)7, OECD, Paris.
V raziskavi je bila uporabljena celična linija za opredelitev učinkov na posebne encime in vmesne hormone, kot je progesteron (2).
Chapter B.53 of this Annex, Developmental Neurotoxicity Study
Opredelitve in kratice, uporabljene v okviru te preskusne metode, so opisane v Dodatku.
Chapter B.54 of this Annex, Uterotrophic Bioassay in Rodents:
Podroben protokol, vključno z navodili za pripravo raztopin, gojenje celic in izvajanje različnih vidikov preskusa, je na voljo v dodatkih I–III k dokumentu OECD 'Multi-Laboratory Validation of the H295R Steroidogenesis Assay to Identify Modulators of Testosterone and Estradiol Production' (4).
A short-term Screening Test for Oestrogenic Properties
V biosintezo spolnih steroidnih hormonov je vključenih pet različnih encimov, ki katalizirajo šest različnih reakcij.
Chapter B.55 of this Annex, Hershberger Bioassay in Rats:
Encimska pretvorba holesterola v pregnenolon z encimom za cepitev stranske verige holesterola (CYP11A) iz družine citokromov P450 (CYP) predstavlja prvi korak v zaporedju biokemijskih reakcij, ki se končajo s sintezo steroidnih končnih proizvodov.
A Short-term Screening Assay for (Anti)Androgenic Properties
Glede na vrstni red naslednjih dveh reakcij se steroidogenska pot razdeli na dve poti, in sicer Δ5-hidroksisteroidno pot in Δ4-ketosteroidno pot, ki se končata s proizvodnjo androstendiona (slika 1).
OECD (2009), Guidance Document for Histologic Evaluation of Endocrine and Reproductive Test in Rodents, Series on Testing and Assessment, No 106, OECD, Paris.
Androstendion se pretvori v testosteron (T) s pomočjo 17β-hidroksisteroidne dehidrogenaze (17β-HSD).
OECD (2011), Guidance Document on the Current Implementation of Internal Triggers in the Extended One Generation Reproductive Toxicity Study in the United States and Canada, Series on Testing and Assessment, No 117, ENV/JM/MONO(2011)21, OECD, Paris.
Testosteron je tako vmesni kot končni hormonski produkt.
Extended One Generation Reproductive Toxicity Study, Series on Testing and Assessment, No 151, OECD, Paris.
Pri moškem se lahko T pretvori v dihidrotestosteron (DHT) s 5α-reduktazo, ki se nahaja v celičnih membranah, jedrni ovojnici in endoplazmatskem retikulumu tarčnih tkiv androgenega delovanja, kot so prostata in semenski mešički.
Measures and observations included in the functional observational battery (Cohort 2A)
DHT je kot androgen znatno močnejši kot T in se prav tako šteje za končni hormon.
Home Cage & Open Field
Pri preskusu celic H295R se DHT ne meri (glej odstavek 10).
Manipulative
Encim na steroidogenski poti, ki pretvori androgene kemikalije v estrogene kemikalije, je aromataza (CYP19).
Physiologic
CYP19 pretvori T v 17β-estradiol (E2) in androstendion v estron.
Posture
E2 in T se štejeta za končna hormona steroidogenske poti.
Ease of removal
Specifičnost aktivnosti liaze CYP17 se med vrstami razlikuje pri vmesnih substratih.
Temperature
Pri človeku daje encim prednost substratom Δ5-hidroksisteroidne poti (pregnenolon), pri podgani pa imajo prednost substrati Δ4-ketosteroidne poti (progesteron) (19).
Involuntary Clonic & Tonic
S takšno razliko aktivnosti liaze CYP17 se lahko razložijo nekatere razlike v odzivu na kemikalije, ki spreminjajo steroidogenezo in vivo in so odvisne od vrst (6).
Ease of handling
Dokazano je, da celice H295 najbolj točno odražajo izražanje adrenalnih encimov in vzorec proizvajanja steroidov pri odraslem človeku (20), vendar je znano, da izražajo encime tako za Δ5-hidroksisteroidne kot tudi za Δ4-ketosteroidne poti za sintezo androgenov (7) (11) (13) (15).
Palpebral Closure
Steroidogenska pot v celicah H295R
Muscle Tone
Encimi so v ležečem tisku, hormoni so v odebeljenem tisku, puščice pa označujejo smer sinteze.
Pupil response
Sivo ozadje označuje kortikosteroidne poti/produkte.
Piloerection
Poti spolnih steroidov/produktov so obkroženi.
Approach Response
CYP = citokrom P450;
Pupil size
HSD = hidroksisteroidna dehidrogenaza;
Salivation
DHEA = dehidroepiandrosteron.
Touch Response
Človeška adenokarcinomska celična linija H295R je uporaben model in vitro za preiskovanje učinkov na sintezo steroidnih hormonov (2) (7) (8) (9) (10).
Lacrimation
V celični liniji H295R se izražajo geni, ki kodirajo vse ključne encime za zgoraj navedeno steroidogenezo (11) (15) (slika 1).
Auditory Response
To je edinstvena lastnost, ker je izražanje teh genov in vivo specifično za tkiva in razvojno fazo, pri čemer se običajno v enem tkivu ali eni razvojni fazi ne izražajo vsi geni, ki sodelujejo pri steroidogenezi (2).
Vocalisations
Celice H295R imajo fiziološke značilnosti consko nediferenciranih človeških fetalnih celic nadledvičnice (11).
Tail Pinch Response
Celice predstavljajo edinstven sistem in vitro, ker so sposobne proizvesti vse steroidne hormone, ki se nahajajo v skorji nadledvične žleze in spolnih žlezah, kar omogoča preskušanje učinkov na sintezo kortikosteroidov in proizvajanje spolnih steroidnih hormonov, kot so androgeni in estrogeni, čeprav je bil preskus validiran le za zaznavanje T in E2.
Rearing
Spremembe, ki jih preskusni sistem zabeleži v obliki spremembe proizvodnje T in E2, so lahko rezultat številnih različnih interakcij preskusnih kemikalij s steroidogenimi funkcijami, ki se izražajo s celicami H295R.
Righting Response
Vključujejo modulacijo izražanja, sintezo ali funkcijo encimov, ki sodelujejo pri proizvajanju, pretvorbi ali odstranitvi steroidnih hormonov (12) (13) (14).
Gait Abnormalities
Zaviranje proizvajanja hormonov je lahko posledica neposredne konkurenčne vezave z encimom na poti, vpliva na kofaktorje, kot sta NADPH (nikotinamid adenin dinukleotid fosfat) in cAMP (ciklični adenozin monofosfat), in/ali povečanja steroidne presnove ali supresije izražanja genov nekaterih encimov na poti steroidogeneze.
Landing Foot Splay
Medtem ko je lahko zaviranje funkcija neposrednih ali posrednih postopkov pri proizvajanju hormonov, je indukcija običajno posredna, na primer z vplivanjem na kofaktorja, kot sta NADPH in cAMP (kot v primeru forskolina), zmanjšanjem steroidne presnove (13) in/ali povečanjem izražanja genov za sintezo steroidov.
Arousal
Preskus celic H295R ima več prednosti:
Forelimb Grip Strength
omogoča zaznavanje tako povečanja kot tudi zmanjšanja proizvajanja T in E2,
Stereotypy
omogoča neposredno oceno možnih učinkov kemikalije na sposobnost preživetja celic/citotoksičnost.
Stains
celična linija H295R je na voljo na tržišču.
Respiratory Abnormalities
Glavne omejitve preskusa so naslednje:
Chemical
ker se v njem ne meri DHT, se ne pričakuje zaznavanje kemikalij, ki zavirajo 5α-reduktazo, pri čemer se lahko v tem primeru uporabi Hershbergerjev preskus (16),
A substance or a mixture.
preskus celic H295R ne bo zaznal kemikalij, ki vplivajo na steroidogenezo prek vpliva na os hipotalamus – hipofiza – spolne žleze (HPG), ker se to lahko proučuje le pri nepoškodovanih živalih.
Test Chemical
V preskusu se lahko zaznajo kemikalije, ki običajno zavirajo ali sprožijo encime poti steroidogeneze.
Any substance or mixture tested using this test method.
Preskus se običajno opravi pod standardnimi pogoji za celične kulture na plošči s 24 jamicami za gojenje kulture.
B.57 H295R STEROIDOGENESIS ASSAY
Po 24-urni aklimatizaciji na ploščah z več jamicami so celice 48 ur izpostavljene sedmim koncentracijam preskusne kemikalije v vsaj treh ponovitvah.
This test method is equivalent to OECD Test Guideline (TG) 456 (2011).
Topilo ter znan zaviralec in povzročitelj proizvajanja hormonov se v nespremenljivi koncentraciji preskusita kot negativni in pozitivni kontrolni vzorec.
The OECD initiated a high-priority activity in 1998 to revise existing, and to develop new, test guidelines for the screening and testing of potential endocrine disrupting chemicals.
Ob koncu obdobja izpostavljenosti se iz vseh jamic odstrani gojišče.
The 2002 OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupting Chemicals comprises five levels, each level corresponding to a different level of biological complexity (1).
Sposobnost preživetja celic v posamezni jamici se analizira takoj po odstranitvi gojišča.
The in vitro H295R Steroidogenesis Assay (H295R) described in this test method utilises a human adreno-carcinoma cell line (NCI-H295R cells) and constitutes a level 2 “in vitro assay, providing mechanistic data”, to be used for screening and prioritisation purposes.
Koncentracije hormonov v gojišču se lahko izmerijo z uporabo različnih metod, vključno s kompleti za hormonske meritve, ki so na voljo na tržišču, in/ali instrumentalnimi tehnikami, kot je tekočinska kromatografija z masno spektrometrijo (LC-MS).
Development and standardisation of the assay as a screen for chemical effects on steroidogenesis, specifically the production of 17β-oestradiol (E2) and testosterone (T), was carried out in a multi–step process.
Podatki so izraženi kot razmerje spremembe glede na kontrolni vzorec s topilom in najnižjo koncentracijo z opaženim učinkom (LOEC).
The H295R assay has been optimised and validated (2) (3) (4) (5).
Če je preskus negativen, se največja preskušena koncentracija sporoči kot koncentracija brez opaznega učinka (NOEC).
The objective of the H295R Steroidogenesis Assay is to detect chemicals that affect production of E2 and T. The H295R assay is intended to identify xenobiotics that have as their target site(s) the endogenous components that comprise the intracellular biochemical pathway beginning with the sequence of reactions from cholesterol to the production of E2 and/or T. The H295R assay is not intended to identify chemicals that affect steroidogenesis due to effects on the hypothalamic-pituitary-gonadal (HPG) axis.
Sklepne ugotovitve glede sposobnosti kemikalije, da vpliva na steroidogenezo, morajo temeljiti na vsaj dveh neodvisnih ponovitvah preskusa.
The goal of the assay is to provide a YES/NO answer with regard to the potential of a chemical to induce or inhibit the production of T and E2;
Prvi potek preskusa lahko deluje kot ponovitev za ugotavljanje območja, pri čemer se koncentracije za drugo ali tretjo ponovitev po potrebi naknadno prilagodijo, če nastanejo težave v zvezi s topnostjo ali citotoksičnostjo ali če se zdi, da je kemikalija aktivna na robu območja preskušane koncentracije.
however, quantitative results may be obtained in some cases (see paragraphs 53 and 54).
POSTOPEK V ZVEZI S KULTURAMI
The results of the assay are expressed as relative changes in hormone production compared with the solvent controls (SCs).
Celična linija
The assay does not aim to provide specific mechanistic information concerning the interaction of the test chemical with the endocrine system.
Celice NCI-H295R na tržišču zagotavlja American Type Culture Collections (ATCC) po podpisu sporazuma o prenosu materiala [14].
Research has been conducted using the cell line to identify effects on specific enzymes and intermediate hormones such as progesterone (2).
Uvod
Definitions and abbreviations used in this test method are described in the Appendix.
Zaradi sprememb zmogljivosti celic za proizvajanje E2 s staranjem/večanjem pasaž (2) je treba celice pred uporabo gojiti v skladu s posebnim protokolom, pri čemer je treba zabeležiti število pasaž od odtajanja celic ter število pasaž, pri katerem so bile celice zamrznjene in shranjene v tekoči dušik.
A detailed protocol including instructions on how to prepare solutions, cultivate cells and perform various aspects of the test is available as Appendix I-III to the OECD document “Multi-Laboratory Validation of the H295R Steroidogenesis Assay to Identify Modulators of Testosterone and Estradiol Production” (4).
Prvo število označuje dejansko število pasaž celic, drugo število pa število pasaž, pri katerem so bile celice zamrznjene in shranjene.
Five different enzymes catalysing six different reactions are involved in sex steroid hormone biosynthesis.
Celice, ki so bile zamrznjene po peti pasaži in odtajane ter so se nato trikrat delile (4 pasaže, pri čemer se sveže odtajane celice štejejo kot pasaža 1) po ponovnem gojenju, bi bile na primer označene s pasažo 4,5.
Enzymatic conversion of cholesterol to pregnenolone by the cytochrome P450 (CYP) cholesterol side-chain cleavage enzyme (CYP11A) constitutes the initial step in a series of biochemical reactions that culminate in synthesis of steroid end-products.
Primer označevanja s številkami je naveden v Dodatku 1 k validacijskemu poročilu (4).
Depending upon the order of the next two reactions, the steroidogenic pathway splits into two paths, the Δ5-hydroxysteroid pathway and Δ4-ketosteroid pathway, which converge in the production of androstenedione (Figure 1).
Založno gojišče se uporablja kot osnova za obogatena gojišča ali gojišča za zamrzovanje.
Androstenedione is converted to testosterone (T) by 17β-hydroxysteroid dehydrogenase (17β-HSD).
Obogateno gojišče je potreben sestavni del gojenja celic.
Testosterone is both an intermediate and end-hormone product.
Gojišče za zamrzovanje je posebej zasnovano tako, da omogoča zamrzovanje celic za dolgoročno shranjevanje brez posledic.
In the male, T can be converted to dihydrotestosterone (DHT) by 5α-reductase, which is found in the cellular membranes, nuclear envelope, and endoplasmic reticulum of target tissues of androgenic action such as prostate and seminal vesicles.
V Nu-serumu (ali primerljivem serumu z enakimi lastnostmi, ki dokazano zagotavlja podatke, ki izpolnjujejo zahteve glede izvedbe preskusa in kontrole kakovosti), ki je sestavina obogatenega gojišča, je treba analizirati za osnovne koncentracije T in E2.